Error Message Box

[Guest]

I want to write a if function that would tell the user using a message box
that an incorrect type has been entered. For example, the correct type is a
number not a letter or anything else. I want the function to post error
message if it is the wrong type and leave the input in the cell if everything
is OK.

 

[Guest]

Instead of resorting to a function, why not use Data Validation on the cell?
Data/Validation/Allow Custom, enter this formula (substitute the active cell
for A1 in the following)
=NOT(ISERROR(1*A1)) then click the Error Alert tab and enter the appropriate
message.
Bob Umlas
Excel MVP