Start running on button press

[Assault]

I want the script to start after a button on the gui is pressed, I'm using this :

While 1
    $nMsg = GUIGetMsg()
    Switch $nMsg
        Case $GUI_EVENT_CLOSE
            exit
        Case $nmsg = $Button1
            call("main")    
        Case $nmsg = $Button2
           Exit

    EndSwitch
WEnd

but it starts the script before the button is pressed.

[Zedna]

While 1
    $nMsg = GUIGetMsg()
    Switch $nMsg
        Case $GUI_EVENT_CLOSE
            exit
        Case $Button1
            call("main")    
        Case $Button2
           Exit

    EndSwitch
WEnd

[eltorro]

While 1
    $nMsg = GUIGetMsg()
    Select $nMsg
        Case $nMsg = $GUI_EVENT_CLOSE
            exit
        Case $nMsg = $Button1
           main()   
        Case $nMsg = $Button2
          Exit
    EndSelect
WEnd

Func main()
    Msgbox(266288,"No Title","$Button1 pressed")
EndFunc

Eltorro