MouseMove(+x/+y)

Hey, I'm writing a project, witch should do some stuff for me, my problem is to move the mouse:


So my problem is, that i also want to move the mouse, if it is always central positioned, so if i do it like the code above
it tries to get to the position tries and tries, and moves to much(more then x/y). So I just want to move the mouse (+x/+y) If you know what I mean...