Click on your cell and then go to the 'Data' tab at the top menu and click on
Validation. You can then select 'decimal' for what's allowed and allow
anything between -99999999999 and 99999999999. If someone enters letters
instead of numbers it will provide an error message, which you can specify
under the 'Error Alert' tab on that validation area.

TM

"RTP" wrote:

Is there any way with a formula to make sure a cell is numeric and to post an
error message if it is NOT numeric???