Can Save Labels To The DB But Not The Content Of DropDownLists !

hi there, i have a payment page which uses javascript to calculate payments and what remains etc. That all works fine, the problem i have is that when you are finished and you go to the next page it should save all of the records to the order table where the order_id = a querystring. Now i have tried using an insert method and an update method, not really sure whats the difference when putting data into an existing record. What happens though is that i can save the contents of labels etc but it wont save the content of dropdown lists (of which there are 2) i just cant work it out, i have posted my code below

 string strOrderID = Convert.ToString(Request.QueryString["OrderID"]);

string strDiscountPercent = Convert.ToString(5656);double dblDiscountMoney = Convert.ToDouble(txtDiscountMoney.Text);

string strPaymentMethod1 = ddlPaymentMethod1.SelectedValue;double dblPaymentAmount1 = Convert.ToDouble(txtPaymentAmount1.Text);

string strPaymentRecipt1 = txtPaymentRecipt1.Text;string strPaymentMethod2 = ddlPaymentMethod2.SelectedValue;

double dblPaymentAmount2 = Convert.ToDouble(txtPaymentAmount2.Text);string strPaymentRecipt2 = txtPaymentRecipt2.Text;

 string sConnectionStringCustInfo = "my connection string";

SqlConnection objConnOID = new SqlConnection(sConnectionStringCustInfo);

//This is the sql statement.using (objConnOID)

{

objConnOID.Open();

 string sqlUpDate = "UPDATE tbl_order SET discount_Percent = " + txtDiscountPercent.Text +

", discount_money = " + dblDiscountMoney + ", payment_method1 = " + strPaymentMethod1 +   =========== this is the problem line here!

", payment_amount1 = " + dblPaymentAmount1 + ", payment_ref1 = " + strPaymentRecipt1 +

", payment_amount2 = " + dblPaymentAmount2 +", payment_ref2 = " + strPaymentRecipt2 +

 

"WHERE order_ID = " + strOrderID;

 

 

 

SqlCommand objCmd1 = new SqlCommand(sqlUpDate, objConnOID);

 

try

{

 

objCmd1.ExecuteNonQuery();

}

 

and because it throws an error it wont update the database with any other record. does anyone have any ideas, i have spent hours last night trying to figure this one out and im sure its simple! but i need some help!

 

Cheers

Jez