.Net form focus

Question

I Have a .net form with multiple controls in it.. Textbox , labels ... When the form is shown on screen the textbox get the focus by default. When i try to scroll the form using mouse scroll wheel the scroll messages are basically going to Textbox and hence the form is not getting scrolled..

I tried setting

textbox.capture = false
form.capture = true; 
form.focus();

But nothing seems to get the attention away from the textbox. Any clue as how to force the form to get the mouse events rather that it's controls??