Getting Error While Tracking Datakey

i am getting this error while tracking my datakey.. i am not sure why my datakey index is coming out of range.. here is my code :

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
var dataKeys = GridView1.DataKeys[e.Row.RowIndex];
dataKeys.Value.ToString();
Label1.Text = "The key field value for the displayed record is " + dataKeys.Value.ToString();
}

Header Part Of the GridView:

</ItemTemplate>
</asp:TemplateField>
</Columns>
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White"
/>
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<EditRowStyle BackColor="#999999" />
<AlternatingRowStyle BackColor="White" ForeColor="#284775" />
</asp:GridView>
<script language="javascript" type="text/javascript">
function viewProfile(selectedRowIndex, firstName) {
//alert(firstName);
//var customGridView = document.getElementById('<%= CustomGridView.ClientID %>');
var customGridView = document.getElementById('GridView1');
if (customGridView) {
var row = customGridView.rows[parseInt(selectedRowIndex) + 1];
//var cell = customGridView.rows[parseInt(selectedRowIndex) + 1].cells[0];
// alert(row.cells[0].innerHTML);
// alert(row.cells[1].innerHTML);
// alert(row.cells[2].innerHTML);
// alert(row.cells[3].innerHTML);
// alert(row.cells[4].innerHTML);
window.open('detatil.aspx?coaid=' + row.cells[1].innerHTML + '&fnomia=' + row.cells[2].innerHTML, "", "scrollbars=no,height=300,width=300");
}
}
</script>

The error is: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index