Delete Data From Gridview Which Is Using Datasource And SP Using Wizard

I am using a gridview to select, delete and update data in database. I have written a single SP for doing all these operation. Based on a parameter SP decides which operation to perform. Here is the image of my gridview

<asp:GridView ID="GridView1" runat="server" DataSourceID="dsDomain"
AllowPaging="True" AllowSorting="True" AutoGenerateColumns="False"
DataKeyNames="DomainId" >
<Columns>
<asp:CommandField ShowDeleteButton="True" ShowEditButton="True" />
<asp:BoundField DataField="DomainId" HeaderText="DomainId"
InsertVisible="False" ReadOnly="True" SortExpression="DomainId">
</asp:BoundField>
<asp:BoundField DataField="Domain" HeaderText="Domain"
SortExpression="Domain">
</asp:BoundField>
<asp:BoundField DataField="Description" HeaderText="Description"
SortExpression="Description" >
</asp:BoundField>
<asp:BoundField DataField="InsertionDate" HeaderText="InsertionDate"
SortExpression="InsertionDate">
</asp:BoundField>
</asp:GridView>
Data Source that I am using is here
<asp:SqlDataSource ID="dsDomain" runat="server"
ConnectionString="<%$ ConnectionStrings:conLogin %>"
SelectCommand="Tags.spOnlineTest_Domain"
SelectCommandType="StoredProcedure" CancelSelectOnNullParameter="False"
DeleteCommand="Tags.spOnlineTest_Domain" DeleteCommandType="StoredProcedure" OnDeleting="DomainDeleting">
<SelectParameters>
<asp:Parameter ConvertEmptyStringToNull="true" DefaultValue="" Name="DomainId" Type="String" />
<asp:Parameter ConvertEmptyStringToNull="true" DefaultValue="" Name="Domain" Type="String" />
<asp:Parameter ConvertEmptyStringToNull="true" DefaultValue="" Name="Description" Type="String" />
<asp:Parameter DefaultValue="1" Name="OperationType" Type="Byte" />
</SelectParameters>
<DeleteParameters>
<asp:ControlParameter ControlID="GridView1" Name="DomainId"
PropertyName="SelectedValue" Size="4" Type="Int32" />

Select operation is working fine. But when I tried to delete, it says Procedure or Function 'spOnlineTest_Domain' expects parameter '@Domain', which was not supplied But I am supplying this parameter, as My Stored procedure calling is like this

EXEC Tags.spOnlineTest_Domain NULL, NULL, NULL, 1 // For Select last parameter will be 1
EXEC Tags.spOnlineTest_Domain "SelectedRow's DomainId), NULL, NULL, 4 // For Delete last parameter will be 4

My procedure has 4 parameters where last parameter will be set by programmer which will tell the program for what kind of operation to be performed. For Select only last parameter has to be Not Null. For Delete first and last parameter cannot be NULL. My first Delete parameter is Primary key of the table. I am passing this value, when a user selects a row and hit delete. I am not sure by using PropertyName="SelectedValue", will I get the right value of the ID.