var divName = 'mydiv';
var offX = 15;
var offY = 15;

function mouseX(evt) {
	if (!evt) evt = window.event; if (evt.pageX) return evt.pageX; else if (evt.clientX)return evt.clientX + (document.documentElement.scrollLeft ?  document.documentElement.scrollLeft : document.body.scrollLeft); else return 0;
}
	
function mouseY(evt) {
	if (!evt) evt = window.event; if (evt.pageY) return evt.pageY; else if (evt.clientY)return evt.clientY + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop); else return 0;
}
	
function follow(evt) {
   if (document.getElementById) {
  	var obj = document.getElementById(divName).style; 
  	obj.visibility = 'visible';   
  	obj.left = (parseInt(mouseX(evt))+offX) + 'px';
  	obj.top = (parseInt(mouseY(evt))+offY) + 'px';
    }
}

function stopIt(evt) {
   if (document.getElementById) {
  	var obj = document.getElementById(divName).style; 
  	obj.visibility = 'hidden';   
    }
}
    
function callFollow(text) {
  	document.getElementById(divName).innerHTML = text;
	document.onmousemove = follow;
}

function stopFollow() {
	document.onmousemove = stopIt;
}