asp.net insertCommand resulting in NULL values - asp.net

Question

I have two listboxes whose values are sent into a TableC via a button.
<asp:SqlDataSource ID="sql1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionDataBase %>"
SelectCommand="SELECT [Name] + ' (' + [CNbr] + ')' AS FullName, [CNbr] AS CNum FROM [TableA] ORDER BY [Name]">
</asp:SqlDataSource>
<asp:ListBox ID="lst1" runat="server" DataSourceID="sql1" DataTextField="FullName" DataValueField="CNum" AutoPostBack="true">
</asp:ListBox>
<asp:SqlDataSource ID="sql2" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionDataBase %>"
InsertCommand="INSERT INTO [TableB] ([CNbr], [RDate]) VALUES (#CNbr, #RDate)"
<InsertParameters>
<asp:Parameter Name="CNbr" Type="String" />
<asp:Parameter Name="RDate" Type="DateTime" />
</InsertParameters>
<asp:ImageButton ID="ibnCheckOutBtn" runat="server"
ImageUrl="./images/vidCheckOutButton.png" onclick="ibnCheckOutBtn_Click" />
ASPX.CS file:
protected void ibnBtn_Click(object sender, ImageClickEventArgs e)
{
sql2.Insert();
}
I don't really know C# and my class doesn't cover most C#, so I am looking for a solution that doesn't use a lot of behind-code. The error I get is:
Cannot insert the value NULL into column 'CNbr', table 'TableB'; column does not allow nulls. INSERT fails. The statement has been terminated.
However, nulls should not occur because the values are taken from a fully populated listbox. Help?

Answer 1

You will need to assign the values to sql2 insert parameters in a similar way as follows:
protected void ibnBtn_Click(object sender, ImageClickEventArgs e)
{
sql2.InsertParameters["CNbr"].DefaultValue = this.FindControl("lst1").SelectedValue;
sql2.InsertParameters["RDate"].DefaultValue = DateTime.Now.ToString();
sql2.Insert();
}