Triangle from mouse

1

i want to make a tiangle appear from the mouse like the first pic on this site

[IMG]http://www.actionscript.org/tutorials/advanced/Mouse_Angle_Detection_II/index.shtml[IMG/]

this is the code im using :

onClipEvent(enterFrame){
clear()
lineStyle(1,0,100)
MoveTo(this._x,this._y)
lineTo(_xmouse,_ymouse)

lineStyle(1,0,100)
MoveTo(_xmouse,_ymouse)
lineTo(_xmouse,200)

lineStyle(1,0,100)
MoveTo(275,200)
lineTo(_xmouse,200)
}

but i dont know why it isnt working? does anybody else ?