Mouses...why this no work?

Okay why doesn't this work? I'm trying to print the mouxe x/y/z out...but it won't do it...

AppTitle "Test Mouse"
Graphics 800,600,16,2
ShowPointer

While Not KeyHit(1)
WaitMouse()
a$=MouseY
b$=MouseX
c$=MouseZ
Print "mouse x/y/z"+a$+b$+c$
Print MouseX+MouseY+MouseZ

Wend
End