ASP.Net GridView insde AJAX UpdatePanel is not refreshing

Hi

I am binding the grid based\ on the filter option.

When i enter the filter criteria and when i click on the submit button, the grid is not refreshing.

But when i put the post back trigger to the button id and click it it works fine but the page refreshed.

Can any one give me an idea about how to solve the issue without make the page refreshed.