var curElement;
function doMouseMove() {
var newleft=0, newTop = 0
if ((event.button==1) && (curElement!=null)) {
  // position item
  newleft=event.clientX-document.all.OuterDiv.offsetLeft-(curElement.offsetWidth/2)
  if (newleft<0) newleft=0
  curElement.style.pixelLeft= newleft
  newtop=event.clientY -document.all.OuterDiv.offsetTop-(curElement.offsetHeight/2)
  if (newtop<0) newtop=0
  curElement.style.pixelTop= newtop
  event.returnValue = false
  event.cancelBubble = true
}
}

function doDragStart() {
// Do not do default drag operation.
if ("IMG"==event.srcElement.tagName)
  event.returnValue=false;
}

function doMouseDown() {
if ((event.button==1) && (event.srcElement.tagName=="IMG"))
  curElement = event.srcElement
}

document.ondragstart = doDragStart;
document.onmousedown = doMouseDown;
document.onmousemove = doMouseMove;
document.onmouseup = new Function("curElement=null")