Different header for different pages and categories?

I need help in my headers, I’ve seen wordpress blogs where they have a different header for each category and page, I wanted to make something like that for my own portfolio website. But I tried various ways on the forums, and they don’t work… (Probably they don’t work with the template?)

My template is gotten through the wordpress theme generator. http://www.yvoschaap.com/wpthemegen/
And this is the link to my wordpress:　http://futatwins.x10hosting.com/wordpress/

Any help will be greatly appreciated, thank you~!