JavaScript - Mouse X/Y Capture

ie=(document.all)?true:false;
xyChange=false;
X=0;
Y=0;
ie=(document.all)?true:false;
function setMouseXY(e) {
   var tempX;
   var tempY;
   if (ie) {
      tempX=window.event.clientX+document.body.scrollLeft;
      tempY=window.event.clientY+document.body.scrollTop;
   } else {
      tempX=e.pageX;
      tempY=e.pageY;
   }
   if (tempY<0) {tempX=0;}
   if (tempY<0) {tempY=0;}
   if (X!=tempX||Y!=tempY) {
      xyChange=true;
   }
   X=tempX;
   Y=tempY;
   return true;
}
function XYchanged() {
   var ret=xyChange;
   xyChange=false;
   return ret;
}
function beginXYcapture() {
   if (!ie) {
      document.captureEvents(Event.MOUSEMOVE);
   }
   document.onmousemove=setMouseXY;
}
function endXYcapture() {
   document.onmousemove=null;
}