Drop Down Reloads again in IE..How to prevent this?

Hi i was using two drop down box..One for Displaying date followed by another for Dispalying Month..If i Select/Change Month from the 2nd drop down then the 1st drop down ( which is date) automatically loads to Day 1 which is first value..This is the problem im facing in IE but it works well in Firefox..How to overcome this IE issue? Its purely JavaScript and HTML page..Im not uing this concept in Java or any other..