form variables and checking

[slimjim]

I have a form and I want to make sure that the proper information is put in.

Example :
One part of the form a person has to put in only numbers, not letters

Such as 24.99 or 1.99

Or they can leave it blank

but no letters

How can make sure this happens ?

[Mordecai]

Try [man]is_numeric/man.

[slimjim]

Perfect that was what i was looking for...