Wikipedia:Reference desk/Archives/Computing/2010 March 30

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March 30

PHP: Passing a variable between frames

• main.php
  • frame1.php
  • frame2.php

Please enter a number: 3   [SUBMIT]      You entered ________.

-->

Please enter a number: _________   [SUBMIT]      You entered 3.

If I want to pass a variable and its value from main.php to frame1.php, I can use GET method.

<frame src="frame1.php?variable=<?php echo $variable; ?>">

How do I pass a variable from frame1.php to frame2.php?

Let's say frame1.php contains a HTML form. How do I pass a value submitted by frame1.php to frame2.php? -- Toytoy (talk) 01:29, 30 March 2010 (UTC)

In this case, you'd store it in the session. -- Finlay McWalter • Talk 10:16, 30 March 2010 (UTC)

Oops, maybe I misunderstood. If those frames are displayed concurrently then the server-side session won't help, and indeed this isn't a PHP problem. Are you instead talking about Javascript variables? -- Finlay McWalter • Talk 11:34, 30 March 2010 (UTC)

You need to use Javascript for this. I think the easiest way for you would be to make frame1.php change the frame source of frame2 to add a GET method to it. You'd put like this into a SCRIPT declaration in the HEAD of the page:

function updateframe(var) {

parent.frame2.location = "frame2.php?variable="+var;

}

... and just make sure that updateframe() is called when you click submit. You'll also have to make sure that the Javascript is able to get the data from the right field and plop it into the function.

All this requires is that you make sure that your <FRAME> declaration for frame2.php has NAME="frame2" in it. I've used something along these lines for my own projects. Let us know if this is confusing or you need a little more javascript coaching. --Mr.98 (talk) 13:42, 30 March 2010 (UTC)

Error message every time the computer is turned on.

When I turn on the computer and I'm led to the main screen, an error message pops up, saying something like (The English part isn't probably exactly right because my computer isn't in English and I had to translate it):

MaAgent_(9E8B0CC0-AACD-4a03-812B-CB4C6D215209}: MAAgent.exe - Application program error
An order "0x00000000" referenced the memory of "0x00000000". The memory could not be read.
If you want to exit the program, click "Okay".
If you want to debug the program, click "Cancel".

How can I make this error message stop popping up every time I turn my computer on? —Preceding unsigned comment added by 70.68.120.162 (talk) 02:11, 30 March 2010 (UTC)

A number of websites report that it is a program installed by a Samsung MP3 player to protect the player from rogue MP3s and can safely be disabled or uninstalled. You should be able to disable it using MSConfig (Start... Run... MSConfig) or you may be able to uninstall the software from Control Panel. --Phil Holmes (talk) 10:03, 30 March 2010 (UTC)

Clearing logs

If my PC is running ok, should I clear the four Windows (Vista) logs? I've got over 50K events in the security log and 20K in the application. Clarityfiend (talk) 02:24, 30 March 2010 (UTC)

I would, if you can, clear the oldest ones, whilst keeping the newer ones. It might be running fine now but you never know... Chevymontecarlo. 06:39, 30 March 2010 (UTC)

I have found it useful to be able to go back through the logs to find when something broke. For example, using the filtering I was able to send an extract from my event logs to show Microsoft support exactly which update broke something some months earlier. Unless you are really short of disk space, I can see a reasonable case for only deleting logs older than some limit (6 months?) or use the event logging "properties" page to limit the size of the log file. Astronaut (talk) 13:03, 30 March 2010 (UTC)

Back-up options

I've got an iTunes library that I need to back up. I know I have about 3 options - discs, hard drives, or internet storage. Which do you think would be the most effective if I was to create a back up and then leave it for ages without using it. I have heard the CDs can become corrupted eventually, but I'm not so sure. What are your experiences with these and which did you think is the best for my situation? Chevymontecarlo. 06:42, 30 March 2010 (UTC)

Do all three, for extra security. —Preceding unsigned comment added by 82.43.92.25 (talk) 13:03, 30 March 2010 (UTC)

I was just about to write "use DVD recordable discs", but our DVD article, in the section DVD as a backup medium, says that DVD-R and DVD+R discs only last 2 to 15 years. This was shocking to me, actually. Our backup article's Storage media section doesn't offer a lot of hope as far as long-term storage goes. (This link is about a very long term backup solution that nobody reading this will ever utilize.) Comet Tuttle (talk) 16:31, 30 March 2010 (UTC)

I believe that the standard advice is to assume that whatever backup system you choose may fail. But if you regularly verify that it's possible to restore from it, you'll notice when failure happens. That way, two failures (original and backup) would have to occur in the same short span of time for you to lose data; you're much, much safer that way. This is assuming you take action when the backup system goes kaput. Paul (Stansifer) 18:06, 30 March 2010 (UTC)

I'd say that DVDs are cheaper than hard drives are cheaper than Internet, and Internet is more safe than hard drives are more safe than DVDs (because of the DVD decay issue mentioned above). That's your tradeoff. I'd go for an external hard drive (probably USB) and store it offsite (your office, a relative's house, whatever). Then you should probably check occasionally that it hasn't failed. (no references, sorry) Jørgen (talk) 08:31, 31 March 2010 (UTC)

this is going to sound like a joke, but for real permanent security, you probably want to record it onto high quality analog vinyl disks..... Gzuckier (talk) 07:28, 1 April 2010 (UTC)

this might violate a non-commercial policy, but since I have no COI, ill recommend idrive (idrive.com). Its online backup, and I've used their FREE 2gb service to backup a mix of text files, programs and pictures. You can backup anything, access it online and download it whenever (larger packages are pay, but reasonable). I'd also second the tip on an external harddrive but wait for that since storage prices keep plummeting. Finally, to bring this convo into the 21st century, consider whether you need a backup at all. You must be a big music fan to go through all of this, but between rhapsody, itunes, pandora, etc. Most music you could ever want is pretty easy to get to and often free or by monthly subscription. I don't have a set of great live concerts, though, and I bet you do... 206.53.153.70 (talk) 20:34, 3 April 2010 (UTC)

Electronic office

I do a lot of business paperwork and administration that involves retrieving business letters and other documents from my filing system. Filing the paper away and retrieving it is time consuming. Are there any computer systems available that can do this with electronic copies of the documents? You would scan each paper document as you recieved them from the post/mail, and file and retrieve things electronically rather than physically. Thanks. 84.13.180.45 (talk) 14:51, 30 March 2010 (UTC)

Yes, this is rather common these days. See paperless office. It would take some careful analysis to figure out what the best system for your own office would be. Usually consultants are called in for this kind of thing—you're paying them to know the relevant technologies that would be useful in your specific case. But setting up a simple system that would let you scan paper documents and save them as PDFs to a networked drive (to a folder based on the date, for example), would be really quite trivial with off-the-shelf software. --Mr.98 (talk) 15:26, 30 March 2010 (UTC)

One of the best things you can do is to standardize your file name conventions (I like to use a format similar to <author's user-id>-<project-name>-<date>.<file-extension>; so, for example, "nimur-kitchen-remodeling-2010-03-25.doc" which unambiguously identifies every single file in my system. Then, careful use of folders and subfolders helps organize all the files neatly - I know "who, what, when," for every file without needing to open it. This is exactly what you requested: a computer file system is designed exactly for "filing" documents. These steps require no special software - just diligence and organization on your part. If you want additional features for retrieving documents, you can find a bunch of database software, email/address-book systems, and so forth. Many of these are free; we can help you locate some if you have more specific feature requests. Nimur (talk) 16:24, 30 March 2010 (UTC)

I concur with Nimur. To do what you say, you would scan each document and save it in a good folder hierarchy and with a good naming scheme, so it is findable. No need for consultants. If you wanted to attempt to get fancy, you could also OCR the documents and store the OCR'ed copy in the same folder as the image file. The only reason to do so IMO would be to aid searching (i.e. when you use Windows Desktop Search to say "show me all the .doc files with the words lawsuit impugn electromagnetic supernova tempera carbonized", because those are the terms you remember for sure are in the document. OCRring will make mistakes and miss some words but it is possibly useful.) Comet Tuttle (talk) 17:03, 30 March 2010 (UTC)

Dumping the files into a file system, no matter how well organized, is probably the simplest solution, but it is not the most scalable. It also leaves a lot of room for human error.

Depending on the volume of documents to be archived, and the number and technical ability of the people doing the archiving and retrieving, the naive approach may become very unwieldy. A more complex Document management system may be called for, ideally something that encompasses the entire pipeline.APL (talk) 17:43, 30 March 2010 (UTC)

Our document management system is very vague, because as noted above, the idea is very vaguely defined. Once some specs are laid out, like a desire to query certain types of metadata, we can narrow down on a particular software solution. Nimur (talk) 18:49, 30 March 2010 (UTC)

I brought up consultants because if your business is of any size, knowing what type of scanner/software/server/etc. to buy (out of the world of options and vast differences in price) can be a little complicated if you don't know what you are doing. As APL points out, the difference between simple and scalable is quite large! I have a feeling I would be able to set up a more complicated system for a larger office, but then again, I'm more on the "consultant" end of the spectrum than "asking people on the internet how to set it up" end. --Mr.98 (talk) 11:57, 31 March 2010 (UTC)

Usually each document has more than one attribute that it could be filed under. It probably would have several. The problem then becomes the amount of time required to attach several key words to it. Is there any scanner that works like a reverse printer, where you put today's incoming mail into a tray and it automatically scans each page, preferably doing automatic OCR as well?

A simple problem I have is my wish that I could save or download Hotmail emails to HD - never found out how to do this yet.

Each item would I suppose be some text or keywords attached to a picture of the document. Similarly for emails.

I like the idea of E-Snailer mentioned in the L-mail article - it would be useful and quick. 78.146.180.118 (talk) 19:42, 30 March 2010 (UTC)

There are scanners with document feeders, yes. Depending on the size of your organization and the cost you can afford, how good it will be can vary. Many modern photocopiers can work this way, for example. There are lots of ways you could set up filing systems. One can imagine rather simple solutions that allow files to be entered into a database for later retrieval. --Mr.98 (talk) 16:33, 31 March 2010 (UTC)

Electronic Document and Records Management System is somewhat relevant. Also Records management. 84.13.45.122 (talk) 20:07, 3 April 2010 (UTC)

How to burn a duplicate of a DVD with only one disk drive in Win 7?

In Windows 7, is it possible to burn a copy of a DVD with only one DVD drive? I know I can download a third-party utility or copy the contents of the DVD to my HD, but what I'm curious about is if this is possible using just the software that comes with Windows 7? 67.39.175.2 (talk) 16:17, 30 March 2010 (UTC)

You need a program that can turn the DVD into an ISO image and then a program that will burn the ISO image to a blank DVD. I know that Vista had the ability to burn ISOs, so Windows 7 should also. I don't know if Windows 7 has the capability to create an ISO. -- kainaw™ 16:33, 30 March 2010 (UTC)

(ec) If you have a .iso or .img file (a raw copy of the DVD data), then Windows 7 can burn it. This used to require an external tool, but is now built into Windows. Here's an article from Microsoft TechNet on how to Burn a Disc Image from an ISO or IMG file in Windows 7. However, it appears that generating the .iso file still does require an external tool; this is usually called ripping; it is commonly brought up in the context of copyright infringement and piracy, and Microsoft seems to be erring on the side of caution (or pandering to the Digital Rights Management lobby) by choosing not to include this feature in their operating system, even though it has many legitimate and legal uses. You can find a list of tools that can produce .iso files from a DVD on our articles Comparison of ISO image software and DVD ripper. I recommend InfraRecorder, because it is easy to use, free, lightweight, released under GPL, and recommended by Canonical. Nimur (talk) 16:34, 30 March 2010 (UTC)

In addition to the above, it's worth mentioning that simply imaging a video DVD (whether that necessitates removing its CSS protection or not) is often not enough to allow you to burn a fresh one; there will generally be capacity issues. Almost all commercial video DVDs are dual layer DVD-9, which means the disk can contain up to 7.95 GiB, and in practice you'll generally find the main movie is between 5 and 7 GiB, with maybe another GiB of trailers, featurettes, and other miscellany. Almost all blank DVDs you find are single layer, which means they'll only store 4.37 GiB of data, not enough even for the main movie. So movie copying software will often perform two further tasks - it'll strip out the DVD's structure and all those ancillary things (and often other things you don't need, like alternate angles, multiple audio tracks, and subtitles). Secondly it'll recode the MPEG video stream to a lower quality, making it small enough to fit onto a single layer recordable DVD. This is why a simple image-then-write process often won't work. Now you can get dual layer DVD-R and DVD+R disks (which would allow a direct copy), but they're surprisingly rare and inexplicably expensive. -- Finlay McWalter • Talk 17:28, 30 March 2010 (UTC)

I should have mentioned that this was a data DVD but anyway my question was still answered. I'll check out InfraRecorder and see what CNET recommends. Thanks. 67.39.175.2 (talk) 18:23, 30 March 2010 (UTC)

Do I want a bridge or something else.

I have an existing Dual Band N WiFi setup at my house. In my TV room, I have several wired ethernet devices. What I want is to connect all the wired devices to a 802.11n bridge with one device, they all become wireless (so to speak). But the only Bridges I've found have only a single ethernet port. I guess they want me to buy a bridge for each device? Or hook up a separate router? No thanks! That's a lot of power bricks... and money! So I want a WiFi N bridge and a 3-4 port router all in one. Does such a creature exist? --70.167.58.6 (talk) 23:50, 30 March 2010 (UTC)

My [simultaneous dual frequencies] Apple Airport Extreme matches this description when operates in "extend existing Wifi network" mode. I bet the same is ture for many G and N routers around. --Chan Tai Man 00:48, 31 March 2010 (UTC) —Preceding unsigned comment added by Chantaiman (talk • contribs)

To be specific, you would not "hook up a separate router" but instead "hook up a separate switch" — a 4-port wired switch is about US$20 at the low end. Comet Tuttle (talk) 16:24, 31 March 2010 (UTC)