VS 2010 How to make a textbox array to accept integers, decimals and some negative numbers.

Hello,

I have two arrays in Form1: Array 1 with 40 textboxes and Array 2 with 40 text boxes.

I just do not know how to make all of this textboxes to only accept numbers with one decimal with the possibility of those numbers being negative, not all of them, but some.

I thank the help I could get to solve this.

Nelson