Master Page-Changing Header matching for each page

The MasterPage in .Net is really just another user control (basically) so you can do something like this:

1) Make a public method in your master page class called something like ChangeImage(string pageName). In this method you should have a switch or an if statement that examines the pageName and changes the image accordingly.

2) In each aspx page you can cast the page's master page to an instance of your master page class in the Page_Load event and call the method like this:

((MyMasterPage)this.Page.Master).ChangeImage("products");

Let me know if you need more help than that.