demo.htm<input type="button" onclick="window.open('son.htm',null,'width=400,height=300')" value="Open">son.htm<script language="JavaScript">
var i=0;
var bln = true;
function bao()
{
    if(bln) {
window.moveTo(screen.availWidth-400,screen.availHeight)
window.resizeTo(400,300)
    }
    if(i<300) {window.moveBy(0,-1)
setTimeout(bao,50)
bln = false;
i++;
    }
}
</script>
<body onload="bao()">