How to exclude a character when using Draw Edit Field block?

[Flip]

Hello,

I am using the Draw Edit Field block. I want to know if there is an easy way to exclude an numeric entry that includes a comma. If a "." is entered for a value it should be allowed, but when a "," is used it should give a message like "invalid" or so. Is there an easy way to do this as I am not a programmer?

Thanks

[fxDreema]

I don't know