Asp.net下拉列表值在jquery对话框中没有变化

I have a div , within which I have a button and an asp.net dropdownlist. I see that the dropdownlist value doesnt change. ie. If I select 30 from the dropdownlist, the selected value is still shown as the default value which is 15, Same thing happens when I select 1Hr , 2Hrs , 48Hrs etc.I have a div , within which I have a button and