Add and remove Object as EventListener

[mj]

Hello,

I' add an object method as handler for an event:

var o = new Op_move();
div.addEventListener("mousemove",function(event){o.mouse_move(event);},true);
div.addEventListener("mouseup",function(event){o.mouse_up(event);},true);
o.mouse_click(event);

In the Object Op_move I will remove this eventListeners:
**Not working**
var node=document.getElementById("m");
node.removeEventListener("mousemove",this.mouse_move,true);
event.stopPropagation();

How I can remove a object method from Listeners.

Thanks