<!-- 
var xPos = 20;
var yPos = document.documentElement.clientHeight;
var step = 1;
var delay = 30; 
var height = 0;
var Hoffset = 0;
var Woffset = 0;
var yon = 0;
var xon = 0;
var pause = true;
var interval;
imgpiao.style.top = yPos;

var automove = true;
function setAutoMove(auto)
{	
automove =auto;	
}

function changePos() {

	if(false==automove)
	{
		return;
	}

width = document.documentElement.clientWidth;
height = document.documentElement.clientHeight;
Hoffset = imgpiao.offsetHeight;
Woffset = imgpiao.offsetWidth;
imgpiao.style.left = xPos + document.documentElement.scrollLeft;
imgpiao.style.top = yPos + document.documentElement.scrollTop;
if (yon) {
yPos = yPos + step;
}
else {
yPos = yPos - step;
}
if (yPos < 0) {
yon = 1;
yPos = 0;
}
if (yPos >= (height - Hoffset)) {
yon = 0;
yPos = (height - Hoffset);
}
if (xon) {
xPos = xPos + step;
}
else {
xPos = xPos - step;
}
if (xPos < 0) {
xon = 1;
xPos = 0;
}
if (xPos >= (width - Woffset)) {
xon = 0;
xPos = (width - Woffset);
}
}
function start() {
imgpiao.visibility = "visible";
interval = setInterval('changePos()', delay);
}
start();
// End -->