How to compare two values of two strings

Question

Hi,
How can I compare two strings so that I get the best match.
I have made form1 with two panels.In the upper panel there is a textbox in which user can enter any string and now I want to compare this string with the text property of other forms (form2,form3  etc....). 
If string matches completely with the text property of any particular form then it should display that form on lower panel  in form1 . and if it does not matches , then it should display error in messagebox.
 
How can I do this........