Modal popup shown at the bottom of the page

I'm using 开发者_StackOverflow社区asp.net ajax, with modal popup extender in a web page. The popup appears fine in Firefox and Google Chrome, but it shown at the bottom of the page in IE8. I tried to control the appearance through JavaScript:

var Image1_ModalPopupExtender = $find("Image1_ModalPopupExtender");
Image1_ModalPopupExtender.set_X(100);
Image1_ModalPopupExtender.set_Y(100);
Image1_ModalPopupExtender.show();

and it works in FF and Chr, but still no luck in IE8... any idea?

Funny. asp and IE -> microsoft . Wat happens if you manually set the style of the popup by selecting it via the dom, and not via the object? (so something like document.getElementById('popupid') or $('#popupid') ). Could you alert its left and top before and after you set X and Y?

A bit more information is required in order to better understand/help you. something like an example page.

Solved.. the main problem was that the page was set with HTML doctype... Changing it to XHTML transitional fixed this issue.