Hide gridview on page open

[RBeach1955]

I am new to this but utilizing your website I found the below code and modified it to work with my page to hide and display a gridview. This programming works fine:

<script type="text/javascript">
function hideGrid()
{document.getElementById("Gridview3").style.display = "none";}

function showGrid()
{document.getElementById("Gridview3").style.display = "block";}
</script>

<INPUT Type="button" Value="Show Material List" OnClick="showGrid()">
&nbsp;&nbsp;
<INPUT Type="button" Value="Hide Material List" OnClick="hideGrid()">

<div id="Gridview3">
<asp:GridView ID="GridView3" runat="server" AutoGenerateColumns="False"
DataSourceID="SqlDataSource2"
style="text-align: center; margin-left: 370px;">
<Columns>
<asp:BoundField DataField="ItemID" HeaderText="ItemID" SortExpression="ItemID">
<HeaderStyle Width="50px"></HeaderStyle>
</asp:BoundField>
<asp:BoundField DataField="ItemDesc" HeaderText="ItemDesc" SortExpression="ItemDesc">
<HeaderStyle Width="400px"></HeaderStyle>
</asp:BoundField>
</Columns>
</asp:GridView>
</div>

What I need is to have the gridview hidden when the page opens. If I set the visible property of the gridview to false, I cannot view the page even with the "Show Material List" button created above.