Mouses...why this no work?

Try this:

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 

It should work for you now... BTW, you could do real time with this:

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

While Not KeyHit(1) 
Cls
a$=MouseY() 
b$=MouseX() 
c$=MouseZ() 
Locate 10,10
Print "mouse x/y/z = "+a$+","+b$+","+c$
Wend 
End