MacBook Pro to HP w1907v

Hi. I just connected my 13 inch MacBook Pro to the HP w1907v monitor and I wanna make the HP monitor my mane screen... how can I do that ?

Cause now when I move my mouse all the way up it goes to my MacBook Pro screen. I just wanna make the MacBook Pro screen like a screen saver and I wanna work on the HP screen 🙂