Gmod AutoSelect! Help!

Hey everybody if you are reading this you have clicked the button out there to see whats in here ok so heres the case: A long time ago I joined i gmod zombie server that F***ED up my gmod so now when i scroll the mouse wheel it automatically clicks the weapons which creeps me out and when i then got a new computer it was still there so if anybody have the same problem or know i fix please help me! :wink:

Thanks bye!

Also give more precisions