thanks RPCOyle.. ;)i know i'm so makulit..but please am asking you to stay on touch on resolving this just for today and tomorrow.. 
..regarding on what you've posted i made it already and yet it works but what i wanted to happen is, the input should be done from the arduino going to the vb application..it seems, when i press the switch button from my hardware which is connected to the arduino i can see on the serial monitor the "" then the "" should be sent to the vb application..inshort, there is no more pressing the button that may happen to the vb and no more command button should be added, all the vb should do is receiving the input from arduino..
anybody please help me..