Calling another workbook not working

I don't get it, I just tested this out with a dummie workbook and it worked fine. Now, I'm trying to use it on the workbook I'm working on, and it's not working at all.

The Name of the workbook I'm trying to call another workbook from is called "Freezer Project" and in the "Bio-Analytical" worksheet I'm trying to call the workbook "Bio-Analytical" to call the worksheet "Bio-Analytical" cell A4 while I'm in cell A4 in the "Freezer Project" workbook......When I try to call this using this formula:

=[Bio-Analytical.xls]Bio-Analytical!A4

it won't work!?!?!?

Is this because the names are the same????

Any info will be greatly appreciated.
Thanks
Joe

When a sheet/book name contains certain characters (such as that hyphen), the book/sheet name needs to be enclosed in single quotes. ='[bio-analytical.xls]bio-analytical'!a4

Thanks MrShorty, I read about that before, and I kept trying to mess with the single quotation marks but I couldn't get it to work.....I think I've been staring at a computer screen for way too long.

But thanks it works great now.