changing the form size

when I run my program, I want to make my program size ( not changable )
because when I put the cursor on the program border, I get the ( <-> ), and everybody can change it, so how can I? make it not .......?

In the properties pane for the form in design view, set the border style to 1, 3, or 4

And to note about when you run the program, this is a property that can't be changed during run time I believe.