Header in Masterpage

Question

Hi,

I am defining all my header in different controls, because I am giving some functions in the header like - the user can search products in the searh button in the header.
I want to call these headers according to the name of the page. For each page the header is different. Can anyone tell me    HOW I CAN CHAGE THE HEADER IN MY MASTER PAGE ACCORDING TO THE PAGE WHICH THE USER IS CURRENTLY VISITING.  MY HEADER IS IN 1 EACH CONTROL. For example if the user visits products page, the header will have a text box and button to search products. Can you please tell me how I can call this in master page?

Thanks,