清除ASPX页面中的asp.net数据网格

I have a custom ASPX search page for a CRM 4.0 solution I am working on. I want to be able to clear out the asp.net datagrid I have on the search page. Right now if a person does a search it returns the results in the datagrid but if they do another search and there are no results for the new search the old search results are still in the datagrid. I have a custom ASPX search page for a CRM 4.0