Need help

Hi!! developer,

                     I am working on the payment gateway integration by using the service of a bank. They give me a sample code by using inputs via textboxes. And in the string they use Request.Form["amount"]  . It means "Request.Form["amount"]" it will hold value of the textbox named amount but now i want to use value that will come from  database.
Te bank is using   string.IsNullOrEmpty(Request.Form["amount"]) but when i use    string.IsNullOrEmpty(Request.Form[dt.Rows[0]["amount"].ToString().Trim()]) by using dataset then it is creating error. How i can solve this issue.
Regards
Bharat Bhushan