MsgBox working but shows second time after clicking OK

Hello,
This is my first post to this forum, so I apologize in advance if I am in the wrong place. I am having a problem with a MsgBox (Excel 2010) that I'm hoping to get help with. The message box appears as expected, except when I click OK, it shows a second time. Clicking OK the second time then brings me back to cell C11. What I am trying to do is force the user to enter data into C11. If they click in C11 and do not enter anything, I want a message box to display asking them to enter the value. I'm not sure what I am doing wrong, and am also wondering if there is a better way of doing this.
Here is my code.

Please Login or Register  to view this content.

Thanks in advance!

Hi Stella,

Add the following code before your "If" statement:

Please Login or Register  to view this content.

Add this code following the "End If" Statement:

Please Login or Register  to view this content.

I think that should work. It looks like the routine is actually running twice as on the first run, it enables a second event. If you shut off "Enable Events" it should keep that from happening.

Thanks,

Daniel