Excel macro so workbook can't get advanced to the next page

[buckdog05]

I am trying to implement a macro in Excel so that when certain cells are not filled in the worksheet pops up an error saying they must be filled in before the user advances to the next worksheet in the workbook. I tried to do this with data validation in Excel, but I would like to save the worksheet with a blank cell and have the error message come up after the user worksheet is being used, not when I am editing it. In other words, I can't leave the cell blank after deleting data from it because I get the same error that the users would get.

We want the sheet to work like a web site that requires certain fields to be filled in.

I figure that I need to use a macro to accomplish what I'm trying to but perhaps not? Thanks in advance!

Edited April 12, 2010 by buckdog05