Cocher toutes les Cases dans Telerik RadGrid

J'ai copié le code à partir du lien ci-dessous
Cocher toutes les Cases dans Telerik imbriquée Grille en C#

Comment jamais, quand je lance le code, j'obtiens cette erreur:

0x800a01b6 - Microsoft JScript runtime error: Object doesn't support this property or method

et la 'checkAll(this, gridToCheckAll);' est mis en évidence dans la dynamique de l'exécution de code à l'erreur.

Toute aide serait appréciée.

<script>
var gridToCheckAll = '<%= rgFiles.ClientID %>';
function checkAll(sender, containerID) {
var checked = sender.checked;
var container = document.getElementById(containerID);
var checkboxes = container.getElementsByTagName('input');
for (var i = 0, l = checkboxes.length; i < l; i++) {
if (checkboxes[i] != sender && !checkboxes[i].disabled)
checkboxes[i].checked = checked;
}
}
</script>
<telerik:RadGrid id="rgFiles" runat="server" HorizontalAlign="NotSet" BackColor="darkgray"
AllowPaging="True" PageSize="50" AllowSorting="True"
EnableEmbeddedScripts="true" 
OnNeedDataSource="rgFiles_NeedDataSource"  
OnItemCommand="rgFiles_ItemCommand" 
OnItemDataBound="rgFiles_ItemDataBound" 
OnItemEvent="rgFiles_ItemEvent"
AllowMultiRowSelection="true" Skin="" 
AllowFilteringByColumn="true" EnableLinqExpressions="false" >
<MasterTableView  HorizontalAlign="NotSet" AutoGenerateColumns="false" AllowSorting="True"
Font-Size="7pt" AllowCustomSorting="true" CellPadding="2" CellSpacing="1" BorderWidth="0px"
TableLayout="Fixed" AlternatingItemStyle-Wrap="false" ItemStyle-Wrap="false" 
CommandItemStyle-Wrap="false" >
<FooterStyle CssClass="datagrid-footerstyle" HorizontalAlign="Right" />
<ItemStyle CssClass="datagrid-itemstyle" Wrap="false" Font-Size="XX-Small" Height="15px"/>
<EditItemStyle BackColor="#2461BF" />
<PagerStyle BackColor="#E0E0E0" ForeColor="DimGray" HorizontalAlign="Left" Mode="NextPrevAndNumeric"
NextPageText="next" PrevPageText="prev" AlwaysVisible="True" />
<HeaderStyle CssClass="datagrid-headerstyle" ForeColor="White" />
<FilterItemStyle BackColor="#a9a9a9" />
<AlternatingItemStyle CssClass="datagrid-alternatingitemstyle" />
<ExpandCollapseColumn Visible="False">
<HeaderStyle Width="19px" />
</ExpandCollapseColumn>
<RowIndicatorColumn Visible="False">
<HeaderStyle Width="20px" />
</RowIndicatorColumn>
<Columns>
<telerik:GridTemplateColumn SortExpression="Reviewed"  DataField="Reviewed" HeaderText="<input type='checkbox' id='checkAll' onclick='checkAll(this, gridToCheckAll);'>" 
UniqueName="Reviewed" AllowFiltering="false" >
<ItemTemplate>
<asp:CheckBox ID="cbReviewed" runat="server" OnCheckedChanged="cbReviewed_CheckedChanged" />
</ItemTemplate>
<ItemStyle Wrap="False" HorizontalAlign="Center" VerticalAlign="Top"></ItemStyle>
<HeaderStyle Width="50px"></HeaderStyle>
</telerik:GridTemplateColumn>
InformationsquelleAutor Dan Boone | 2012-12-14