ใช้ GridView ChexBox ค่ะ ตอนนี้ติด error Foreign Key จะต้องส่งงานแล้วช่วยหน่อยนะคะ

        protected void btnSave_Click(object sender, EventArgs e)
        {

            foreach (GridViewRow row in GridView1.Rows)
            {
                SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["BD_TrainingConnectionString"].ConnectionString);
                con.Open();
                CheckBox CheckBox = row.FindControl("chkSelect") as CheckBox;
                if (CheckBox.Checked == true)
                {
                        SqlCommand command = new SqlCommand("INSERT INTO CoursesEmployees(couID, empID)VALUES(@couID, @empID)", con);
                        command.Parameters.AddWithValue("couID", TextBox1.Text);
                        command.Parameters.AddWithValue("empID", CheckBox.Checked);
                        command.ExecuteNonQuery();
                        Response.Redirect("Decou.aspx");                  
                }
                con.Close();
            }

        }