.Freezing
{
color:Red;
background-color:Black;
font-weight:bold;
text-align:left;
border-width:0;
position: relative;
z-index: 10;
}
<asp:Panel ID="Panel1" style="overflow:auto;height:250px" runat="server">
<asp:GridView ID="grid" runat="server">
<HeaderStyle CssClass="Freezing" Height="100px" />
</asp:GridView>
</asp:Panel>
PR
