My movement of banner is not working in IE6, works in IE7 and Firefox, and Safari - Javascript

Hi folks.

I took on a job where I had to get a banner to show up 30 seconds
after the document has loaded in the browser.
This banner also had the requirement that it had to scroll up from
outside of the viewport to its position on the bottom of the browser.

I thought that all was well when I realized that it is not working on
IE6 when I went to a friend's place.
I thought that I should add that I saw it work once on IE6.

I would apprecitate any help.

The url to the page is http://theamazing.onlinewebshop.net/...-kitchens.html

I am accomplishing the task by the following javascript:

function closeAd()
{
document.getElementById("theimage").style.display= "none";
}
function showAd()
{
document.getElementById("theimage").style.display= "block";
moveit();
}
function theadd()
{
document.write("<div id='theimage' style='background-
color:transparent;width:100%;left:0;text-align:center;display:none;
position:fixed;z-index:100;bottom:-140px; height:140px;'>");
document.write("<div style='position:relative;background-
color:#762123; top:41px;left:0;width:100%;height:100px;'></div>");
document.write("<div style='position:absolute;top:0;width:100%;left:
0;text-align:center;'>");
document.write("<a href='somewhere.htm'><img style='border:none;top:
0;height:140px; width:785px;' src='images/LayerAd.png'></a>");
document.write("</div>");
document.write("<a href='' style='font-weight:bold;
color:white;position:absolute;top:60px;right:18px;'
onClick='closeAd(); return false;'>Close</a></div>");
}

function moveit()
{
ypos++;
document.getElementById('theimage').style.bottom = ypos + 'px';
if (ypos<0)
{
setTimeout(moveit,10);
}
}


Thanks,
Terry