>> How to use On key label eg. F1 to run a method in form? <<

OKL's in a production environment are a bad idea because they interrupt whatever is happening at the moment.

A better idea would be to set the form's KeyPreview property to true and put code like this in the form's KeyPress:

IF nKeyCode = -2  && F3
  This.MyMethod()
ENDIF

Using F1 is a bad idea because F1 is used to bring up help.