How to display the usercontrols dynamically according to the menu selected????urgent......

Question

hi all,

I got a doubt in creating usercontrols dynamically in my website...
can anyone pls give a good suggestion for me???
My problem is,
   I have a header usercontrol, footer usercontrol and many body files. I have menus in header to link all the body files. Now, How can i give the link from header usercontrol to other files.
I want to maintain only one aspx file with the header and footer. where, when we click the menu in header, the body page should appear in the same page. How to display the userontrols dynamically according to the menu selected????????

Pls reply soooon...Its very urgent for me.....

thanks in advance