I have a form which has a cell, say A1, that uses a data validation list. I'm locking the form so that users can only use that cell, but I want them to be able to see which cell they can edit. My thought was to use Conditional Formatting on the cell with =isblank(A1). My thought was that the cell would be highlighted so long as they hadn't made a selection. When I applied the rule, it appeared to work - the cell was blank and it was appropriately highlighted; however, when I made a selection from the drop down list the cell remained highlighted. Any thoughts?
Hi Jim
There is no reason why it is not working as your formula is correct.
Take a look at my attached file.
Sorry, missed the file 
Make sure that Workbook calculation is set to Automatic, not Manual, this can be a reason.
You can upload a sample file where this problem can be tested, so we can see what's happening.
I often choose to use standard basic formatting to make things clear to the end user.
In the attached I have used gentle shading across the entire sheet, left the colour out of the required cell and utilized different thicknesses of border to make the cell very obvious - like a form.
You could also use isblank with it - that is often useful when you have created a dozen fields to be completed and users can see their progress as they complete the fields (see the second tab of the attached).
In certain situation, shading may not be useful, especially when you need to print the form (as in my case).
I normally use the lightest shade of grey possible on the cells that needed data entry.
Since all my forms uses VBA, I am able to check to ensure that all compulsory fields are filled in before they can be saved.
Thanks all for the useful comments. I've fixed the problem. In my original post I forgot to mention that cell A1 was actually merged with all cells between A1:AO2. So, thanks to your comments I new the formula should have worked but I changed it from =isblank(A1) to =isblank(A1:AO2). Now it works perfectly.
Glad you figured it out, Jim.
Microsoft really should remove the merge cells feature and replace it with 'Center Across Selection', as this is far less troublesome.
I recommend you change your formatting to use 'Center Across Selection', which you'll find in the Format Cells dialog box under the Alignment tab: Horizontal > Center across selection. Then you can change your formula to =ISBLANK(A1) which is really what you want (I presume).
Mynda
