All Telerik .NET tools and Kendo UI JavaScript components in one package. Now enhanced with:
Protected Sub radGrd_GroupsChanging(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridGroupsChangingEventArgs) Handles radGrd.GroupsChanging
If e.Action = GridGroupsChangingAction.Ungroup Then
If e.Expression.GroupByFields(0).FieldName = "YourFieldName" Then
e.Canceled = True
End If
End Sub