DropDownList width problem

I am facing one strange scenario i.e.

I am using dropdown list in my web form with width as 100px and populates the list from database. But when I view my dropdown list in IE it hides the long text after 100px, but when I view the same form in firefox then the dropdown's list box width is stretched according to the long text size.

How can we achieve the same behavior of firefox in IE too.

Thanks in advance
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