Problem in DataGridview Paging

Question

Dear Friends,
I am having a Data Gridview and had done allow Paging="True"
,on the display i have 10 records and its proper but when i click on the 2nd link at the bottom the gridview is blank.
what could be the mistake.the code is as follows.

 protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        GridView1.PageIndex = e.NewPageIndex;
        GridView1.DataBind();
    }

reply.

Thanks & Regards,
Aamir