var divName = 'eventImg';
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 thumbShow(im) {
  if (im != '')
  {
    var obj = document.getElementById('eventThumb');
    obj.src = '/images/'+im;
    document.onmousemove = follow;
  }
}

function thumbHide() {
  var obj = document.getElementById(divName).style;
  obj.visibility = 'hidden';
  document.onmousemove = "";
}