>Thanks so much Naomi, That was very helpful. You seem to know everything.
>Thanks once again.

Hi Sammy,

The sample in the link was a little bit confusing, I think. Here is what I just got working:

#region SQL DataSource Inserting - setting parameters

    protected void DataSource_Inserting(object sender, SqlDataSourceCommandEventArgs e)
    {
    //    foreach (System.Data.Common.DbParameter par in e.Command.Parameters) {
    //        Response.Write (par.ParameterName + " = " + par.Value.ToString()  + "<br //>") ;
    //    }
        e.Command.Parameters["@PersonType"].Value = ViewState["PersonType"];//this.PersonType ;
    }
    #endregion

I changed from ControlParameter to just Parameter because I didn't want to keep my combobox to enable state. So, I had to use ViewState to set the combo's value.

I could not find a better way except for changing EnableViewState in code (it also worked).

However, somehow the other way didn't sound too good to me.