Incorrect syntax near ','. : I have been running into this error for a while now, and still haven't been able to solve it. I am trying to Update the data in my database, with a button press in a windows form.

I am using SQL 2011.

     private void btnEdit_Click_1(object sender, EventArgs e)
        {
           
            MainMenu mainmenu = new MainMenu();
            SqlCommand cmd = new SqlCommand("Update PresentationSpec SET Pres_name = @Pres_name, Prestor_name = @Prestor_name, Pres_Summary = @Pres_Summary, Est_Length = @Est_Length, Date_Presented = @Date_Presented WHERE Id=" + mainmenu.tbxSelected);
                cmd.Connection=connection;
                connection.Open();
                cmd.Parameters.AddWithValue("@Pres_name", tbxpresName.Text);
                cmd.Parameters.AddWithValue("@Prestor_name", tbxprstorName.Text);
                cmd.Parameters.AddWithValue("@Pres_Summary", rtbSummary.Text);
                cmd.Parameters.AddWithValue("@Est_Length", tbxLength.Text);
                cmd.Parameters.AddWithValue("@Date_Presented", tbxDate.Text);
                cmd.ExecuteNonQuery();
                this.Close();
                Form2 editscreen = new Form2();
                Refresh();
        }

If anyone knows what's wrong, please tell me.