How do I make a custom print setting on Adobe Illustrator CS3?

I have blank thank you cards but none of the media presets fit the size of the cards. They're 4.5x4 in and it won't let me select custom so I can't print them out. Help me please. I have two hours left.How do I make a custom print setting on Adobe Illustrator CS3?
When you open a new document, a window pops up, allowing you to size it any way you want.





In the doucument set up window, you can also select a portrait or landscape orientation, so that your printer can apply the graphics in the proper direction.How do I make a custom print setting on Adobe Illustrator CS3?
From print dialog box select ';Page Setup';a message from Illustrator, click cont. Page size go to ';Manage Custom Sizes';.Click the + or (add) and set your card size and margins. Click Ok twice. The Illustrator dialog will show defined by driver but the sizes will be correct. Report Abuse