>I want to only allow the user to leave a grid line in a form, if what they entered is valid. I have the code for validity checking, but don't understand how to code the valid method so it won't allow them to leave the grid line.

Douglas,

In addition to the others..
If the checking you need is in the field rules/record rule, set the buffering to row buffering. You will not be able to go to another record if your record rule returns false.

I put as much checking in the field rules and the records rule as I possibly can. The advantage is that it has to be coded only once