How to apply themes to the user control?

Question

Hi friends

I have created a user control with name menuUserControl with menu control in it. I have created a user defined property for the user control(menuUserControl) as groupid and when ever I pass groupid to the user control(menuUserControl) in a page, it should use a theme based on the groupid I pass to it. For example if I use two user controls(menuUserControl) one at the top and other at the bottom of the the page with two different groupids like if I pass groupid=1 for top user controls(menuUserControl), it should use theme1 and groupid=2 to the bottom user controls(menuUserControl), it should use theme2. So my problem is that I am unable to apply theme to the user control. I have done some google search but unable to create a theme for a user control. I am only able to apply themes to the server controls. As I am using two user controls i.e menuUserControl as said above, both are displaying same theme. I want to apply two different themes to two user controls(menuUserControl). If any one have any solution or any other alternative, kindly help me please, Its very urgent for me. If you did not understand or you have any doubt, please reply back, I will try to analyze the problem. Hope to get a positive response.

Thanks Wajid