code: function ( arg ) {
  		var type = typeof arg;
  
  		if ( type === "object" ) {
  			var v = document[mouse.view],
  			    x = arg.pageX ? arg.pageX : ( v.scrollLeft + arg.clientX ),
  			    y = arg.pageY ? arg.pageY : ( v.scrollTop  + arg.clientY ),
  			    c = false;
  
  			if ( mouse.pos.x !== x ) {
  				c = true;
  			}
  
  			$.mouse.prev.x = mouse.prev.x = number.parse( mouse.pos.x, 10 );
  			$.mouse.pos.x  = mouse.pos.x  = x;
  			$.mouse.diff.x = mouse.diff.x = mouse.pos.x - mouse.prev.x;
  
  			if ( mouse.pos.y !== y ) {
  				c = true;
  			}
  
  			$.mouse.prev.y = mouse.prev.y = number.parse( mouse.pos.y, 10 );
  			$.mouse.pos.y  = mouse.pos.y  = y;
  			$.mouse.diff.y = mouse.diff.y = mouse.pos.y - mouse.prev.y;
  
  			if ( c && $.mouse.log ) {
  				utility.log( [mouse.pos.x, mouse.pos.y, mouse.diff.x, mouse.diff.y] );
  			}
  		}
  		else if ( type === "boolean" ) {
  			arg ? observer.add( document, "mousemove", mouse.track, "tracking" ) : observer.remove( document, "mousemove", "tracking" );
  			$.mouse.enabled = mouse.enabled = arg;
  		}
  
  		return $.mouse;
  	}
docs: Enables or disables mouse co-ordinate tracking
  
  @method track
  @param  {Mixed} arg Boolean to enable/disable tracking, or Mouse Event
  @return {Object}    $.mouse