Insert statement does not insert any data

[Kadocity]

I have a page where I display a list of groups for my application. There can be multiple users in a group. The group list is implemented with a gridview. Besides the column for the group description, the gridview has a button for adding users to it. When I click this button, the groupid is passed to a new page, on this page there is another gridview with a list of users. The gridview also has a buttonfield for adding that specific user to the group's group id. For this I have an extra table:UserGroup\[code\]usergroupiduseridgroupid\[/code\]My problem is, nothing is inserted into this table, the insert command is executed but something seems to be missing.Here is my code:Markup:\[code\]<asp:Content ID="content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="server"> <asp:GridView OnRowCommand="grdBenutzer_RowCommand" ID="grdBenutzer" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource1"> <Columns> <asp:BoundField ReadOnly="true" DataField="BenutzerID" HeaderText="ID" /> <asp:TemplateField HeaderText="Bezeichnung"> <ItemTemplate> <%# Eval("Bezeichnung")%> </ItemTemplate> <EditItemTemplate> <aspropDownList AppendDataBoundItems="true" runat="server" ID="ddwnBezeichnung" Text='<%# Bind("Bezeichnung")%>'> <asp:ListItem Text="Mitarbeiter" Value="http://stackoverflow.com/questions/15550742/Mitarbeiter"></asp:ListItem> <asp:ListItem Text="Praktikant" Value="http://stackoverflow.com/questions/15550742/Praktikant"></asp:ListItem> <asp:ListItem Text="Azubi" Value="http://stackoverflow.com/questions/15550742/Azubi"></asp:ListItem> <asp:ListItem Text="Umsch