请教JAVASCRIPT如何修改光标样式~~~~网上没找到~~

<script>
var i=0
function xx(e){
e.style.cursor="progress"
i++;
if(i==4)
{i=1}
switch(i)
   {
   case 1:
    e.style.cursor="progress"
     break
   case 2:
     e.style.cursor="wait"
     break
    case 3:
     e.style.cursor="sw-resize"
     break
    case 4:
     e.style.cursor="crosshair"
     break
   }}</script>
<body style="cursor:pointer">
<img src="1.jpg" width="500" height="100"  onmouseover="xx(this)">
</body>