Syntax error in update query using ms access database and .net 4.0

[shobhit9243]

private void update_Click(object sender, EventArgs e)
        {
            OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\shobhit\Documents\Environment_Monitoring.accdb;
Jet OLEDB:Database Password=divya6");
            String sdat = dateTimePicker1.Value.ToShortDateString();
            String la = labs.SelectedItem.ToString();
            String one = "EMI EMC Lab 3rd Floor";
            String two = "Envrionment Lab 2nd Floor";
            String three = "Electrical Performance Test Lab 3rd Floor";
            String four = "Electrical Safety Test Lab 1(first floor)";
            String five = "Electrical Safety Test Lab 2(ground floor)";
            String six = "Electrical Safety Test Lab 3(ground floor)";
            String seven = "Photometry Lab";
            String eight = "Electrical General Lab";
            String tempr = roomtemp.Text;
            String humid = humidity.Text;
            String ll = lightlevel.Text;
            String ln = lnvolt.Text;
            String ne = nevolt.Text;
            String air = airpressure.Text;
 
            if (la.Equals(one))
            {
                Console.WriteLine("hello");
                OleDbCommand cmmd = new OleDbCommand("UPDATE EMI_EMC_LAB SET ROOM_TEMPERATURE=@TEMP,HUMIDITY=@HUMID,LIGHT_LEVEL=@LL,L-N_VOLTAGE=@LN,N-E_VOLTAGE=@NE,AIR_PRESSURE=@AIR WHERE EDDATE=@SDAT", conn);
                cmmd.Parameters.Add("@SDAT", OleDbType.VarChar).Value = sdat;
                cmmd.Parameters.Add("@TEMPR", OleDbType.VarChar).Value = tempr;
                cmmd.Parameters.Add("@HUMID", OleDbType.VarChar).Value = humid;
                cmmd.Parameters.Add("@LL", OleDbType.VarChar).Value = ll;
                cmmd.Parameters.Add("@LN", OleDbType.VarChar).Value = ln;
                cmmd.Parameters.Add("@NE", OleDbType.VarChar).Value = ne;
                cmmd.Parameters.Add("@AIR", OleDbType.VarChar).Value = air;
 
                conn.Open();
                int temp1 = cmmd.ExecuteNonQuery();
                if (temp1 > 0)
                {
                    labs.Text = null;
                    roomtemp.Text = null;
                    humidity.Text = null;
                    lightlevel.Text = null;
                    lnvolt.Text = null;
                    nevolt.Text = null;
                    airpressure.Text = null;
                    MessageBox.Show("Record Successfuly Added");
                }
                else
                {
                    MessageBox.Show("Record Fail to Added");
                }
                conn.Close();
            }

[Rabbit]

You have dashes in your field names. That is a non-standard character and it thinks you are trying to subtract 2 fields. You need to surround your field name with square brackets so it knows it is a field name and you are not trying to subtract. You should avoid using non-standard characters in field names.