apply css to header of gridview

Hi all,

I have tried to apply a css with a repeating background image to the
header of a gridview but without succes.

..gridview
{
background-image: url(images/icon_delete.gif);
background-repeat: repeat-x;
font-size: 2em;
}

and use
<asp:GridView ID="TestGridView" runat="server" EnableViewState="False"
HeaderStyle-CssClass="gridview">

The font is rendered bigger (2em) but I don't see the image. I also
tried other images but no succes.

Someone has a clue what I do wrong?

Thanks
Stijn

tarscher@gmail.com