Search for whole datatable: How to modify it to apply for only shown data fields?

Hi,
I have datatable with data fields (Id(HiddenField), Title, Url, Page and some image buttons for edit, delete etc). When I search from textbox, I press F it sows rows that does not contains any F in words. Another thing is that I want field that starts with F comes on top. How I customize it. or how I achive both things. Thanks.

Atiq