document.write ('<div id="dd" style="position:absolute; left:250px; top:114px; width:100px; height:100px; z-index:1"><a href="http://www.lois.cn" target="_blank"><img src="Linkphoto3.gif" width="300" height="50" border="0"></a></div>');

var xPos = 20;
var yPos = document.body.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;

dd.style.top = yPos;
function changePos() {
width = document.body.clientWidth;
height = document.body.clientHeight;
Hoffset = dd.offsetHeight;
Woffset = dd.offsetWidth;
dd.style.left = xPos + document.body.scrollLeft;
dd.style.top = yPos + document.body.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() {
dd.visibility = "visible";
interval = setInterval('changePos()', delay);

}
function pause_resume() {
if(pause) {
clearInterval(interval);
pause = false;
}
else {
interval = setInterval('changePos()',delay);
pause = true;
}
}
start();