You do not have to use isNumeric nor the do Loop.

I have a method of doing this without using the IsNumeric.

The Application.InputBox method I had stated earlier is a superb way
of getting input in only number  format. If you enter any other format
then an error  will be dispalyed automatically without any need for
further code.

Please use this. To find out how to do it please refer to a previous
posting on the same thread.