Dropdownlist not bound in dim background

In my web page I show loading image with dim开发者_高级运维 background. Dropdown list is not bound inside the dim background .In IE only I experience this problem..How to fix it..

I'm going to guess that you are using Internet Explorer 6. It has a problem where dropdown lists are always shown above all other elements in the page. There are some workarounds for this, but I would recommend simply upgrading your browser, as this bug is fixed in IE7 and later.