how do i change document size in illustrator cs5?

View this guide: http://www.thegraphicmac.com/changing-illustrator-cs4-artboard-orientation

It's for CS4 ... but I think it will apply to 5 as well

Answered Oct, 15 2010

In Adobe Illustrator CS5, to change the page size or orientation of your artboard, use the Artboard Options dialog box or the Artboard options in the Control panel.

Or You could change page size and orientation in the Print dialog box is for printing purposes only.

Answered Nov, 09 2010

To change your Illustrator document orientation, do the following:

First: Click the Document Setup button in the Control Bar, or select Document Setup from the File menu. If you’re a keyboard shortcut-junkie, hit Command + Option + P:

Second: In the Document Setup dialog box that comes up, click the Edit Artboards button at the top of the dialog box:

Third: If you have multiple artboards in your document, click the one you want to edit the orientation/size of. The selected artboard will have a dashed outline around it, along with object handles for manual adjustments.

Fourth: In the Control Bar at the top of your document window, you’ll notice that you have several artboard controls. You can use the presets in the drop-down menu, click the page orientation icons, create or delete artboards, as well as alter the size of your selected artboard via numeric input boxes.

Finally: Commit the changes to your artboard(s) by clicking any tool in the Toolbar, or using any tool-switching keyboard shortcut. Answered Feb, 13 2011

hi, hope the site below will help you...
help.adobe.com/en_US/illustrator/cs/using/WS714a382cdf7d304e7e07d0100196cbc5f-64bea.html Answered Apr, 10 2011

Open the document. Hit Ctrl-P to print, select the Adobe PDF printer in the drop down box, then click on the properties button, then click on the Adobe PDF Settings tab. The top item will be the page size. Click on the drop down box and select the proper page size.
read more details answers.yahoo.com/question/index Answered Apr, 14 2011