Here's the code of my grid
<
telerik:RadGrid ID="Schedule" runat="server" AllowSorting="True" SortingSettings-SortToolTip="<%$ Resources:ToolTipSort %>"
Skin="Office2007" GridLines="None" AutoGenerateColumns="False">
<clientsettings AllowRowsDragDrop="True">
<Scrolling AllowScroll="True" UseStaticHeaders="True" />
<Selecting AllowRowSelect="True"/>
<ClientEvents OnRowDropping="onScheduleRowDropping"/>
</clientsettings>
<mastertableview commanditemdisplay="Top" datakeynames="ID" clientdatakeynames="ID"
gridlines="None" tablelayout="Auto" allowmulticolumnsorting="true">
<CommandItemTemplate>
</CommandItemTemplate>
<GroupByExpressions>
<telerik:GridGroupByExpression>
<SelectFields>
<telerik:GridGroupByField FieldName="DateBegin" FormatString="{0:D}" HeaderText=" "
HeaderValueSeparator=""></telerik:GridGroupByField>
</SelectFields>
<GroupByFields>
<telerik:GridGroupByField FieldName="DateBegin" SortOrder="Ascending"></telerik:GridGroupByField>
</GroupByFields>
</telerik:GridGroupByExpression>
</GroupByExpressions>
<Columns>
<telerik:GridTemplateColumn HeaderText="<%$ Resources:Hour_GridHeader %>" ItemStyle-VerticalAlign="Top"
HeaderStyle-Width="80px" ItemStyle-Width="80px">
<ItemTemplate>
<%
#DataBinder.Eval(Container.DataItem, "Hours")%>
</ItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridTemplateColumn HeaderText="<%$ Resources:Description_GridHeader %>"
ItemStyle-VerticalAlign="Top" HeaderStyle-Width="100%" ItemStyle-Width="100%">
<ItemTemplate>
<span style="position: relative; vertical-align: top">
<asp:Image ID="imgType" runat="server" />
<asp:Label ID="lblDescription" runat="server" Text='<%#DataBinder.Eval(Container.DataItem, "Description")%>'></asp:Label>
</span>
</ItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridTemplateColumn HeaderText="<%$ Resources:Priority_GridHeader %>" HeaderStyle-HorizontalAlign="Center"
ItemStyle-VerticalAlign="Top" ItemStyle-HorizontalAlign="Center" HeaderStyle-Width="90px"
ItemStyle-Width="90px">
<ItemTemplate>
<%
#DataBinder.Eval(Container.DataItem, "PriorityDisplay")%>
</ItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridTemplateColumn ItemStyle-VerticalAlign="Top" HeaderStyle-Width="60px"
ItemStyle-Width="60px">
<ItemTemplate>
<span id="ActionsToolBar" runat="server" onclick="event.cancelBubble=true;">
<telerik:RadToolBar ID="ActionsRadToolBar" runat="server" Skin="Office2007" OnClientButtonClicked="ActionsRadToolBar_OnClientButtonClicked" AppointmentId='<%# Eval("ID") %>'>
<Items>
<telerik:RadToolBarDropDown runat="server" Text="<%$ Resources:ActionsToolBarMenu %>" Width="100%" Height="18px">
<Buttons>
</Buttons>
</telerik:RadToolBarDropDown>
</Items>
</telerik:RadToolBar>
</span>
</ItemTemplate>
</telerik:GridTemplateColumn>
<telerik:GridBoundColumn UniqueName="HasWarningUnavailabilityConflict" DataField="HasWarningUnavailabilityConflict"
Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="HasWarningResourceConflict" DataField="HasWarningResourceConflict"
Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="AppointmentType" DataField="AppointmentType"
Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="Priority" DataField="Priority" Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="IsFinished" DataField="IsFinished" Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="IsCanceled" DataField="IsCanceled" Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="FromOldPlanVersion" DataField="FromOldPlanVersion" Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="ManualCreation" DataField="ManualCreation" Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="VisitType" DataField="VisitType" Display="false">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn UniqueName="IsUnasigned" DataField="IsUnasigned" Display="false">
</telerik:GridBoundColumn>
</Columns>
<NoRecordsTemplate>
<asp:Literal ID="litNoRecords" runat="server" Text="<%$ Resources:NoRecords %>"></asp:Literal>
</NoRecordsTemplate>
</mastertableview>
</telerik:RadGrid>
And I want in OnRowDropping compare the AppointmentType to see if two rows had the same value