ASP.NET

<asp:DropDownList ID="ddlCType" runat="server" 
    DataSourceID="SqlDataSource1" DataTextField="CouponName" 
    DataValueField="CouponTypeID" 
    
        style="top: 309px; left: 389px; position: absolute; height: 11px; width: 97px; z-index: 1" 
        AutoPostBack="True" ontextchanged="DropDownList1_TextChanged">
</asp:DropDownList>

try
{
    ErrorMessage.Text = "";
    cnx.Open();
    SqlCommand insertCmd = new SqlCommand("insert into CouponTransaction(CouponTypeID)values(@Id)", cnx);
    insertCmd.Parameters.Add("@Id", SqlDbType.TinyInt);
    insertCmd.Parameters["@Id"].Value = ddlCType.Text;insertCmd.ExecuteNonQuery();
    ErrorMessage.Text = "Records inserted successfully";
    cnx.Close();
}

[WebMethod]   
        public String CardWithPerson(string persId, string projectId, string username, string pw)   
        {   
            xmlfile = "<?xml version=\"1.0\" encoding=\"utf-8\" ?> "  
            + "<soap:Envelope xmlns:soap=\"http://www.w3.org/2001/12/soap-envelope\">"  
            +"<soap:Body>"  
            +"<PS_CardsWithPersonReq xmlns=\"http://tempuri.org\">"  
           +"<WebAuthenticate>"  
            +" <WebUser>"+username+"</WebUser>"  
            +" <WebPass>"+pw+"</WebPass>"  
            +" <WebIp>"+Context.Request.UserHostAddress+"</WebIp>"  
            +" <WebMd>0123456789ABCDEF0123</WebMd>"  
            +" </WebAuthenticate>"  
            +"<PersNr>"+persId+"</PersNr>"  
            +"<Lang>E</Lang>"  
            +"<ProjCode>"+projectId+"</ProjCode>"  
            +"</PS_CardsWithPersonReq>"  
            +"</soap:Body>"  
            +"</soap:Envelope>";   
            r = HttpSOAPRequest(xmlfile, null);   
            result = r.ReadToEnd();   
            return result;   
        }   
  
StreamReader HttpSOAPRequest(String xmlfile, string proxy)   
        {   
            XmlDocument doc = new XmlDocument();   
            doc.LoadXml(xmlfile);   
               
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://211.144.244.244:7871");   
            if (proxy != null) req.Proxy = new WebProxy(proxy, true);   
            req.Headers.Add("SOAPAction", "\"\"");   
            req.ContentType = "text/xml;charset=\"utf-8\"";   
            req.Accept = "text/xml";   
            req.Method = "POST";   
            Stream stm = req.GetRequestStream();   
            doc.Save(stm);   
            stm.Close();   
            WebResponse resp = req.GetResponse();   
            stm = resp.GetResponseStream();   
            StreamReader strmReader = new StreamReader(stm);   
            return strmReader;   
        }  

protected void Button1_Click(object sender, EventArgs e)   
        {   
            nl.test.testsoap.Service1 serv = new WebApplication1.nl.test.testsoap.Service1();   
  
            Response.Write(serv.CardWithPerson(textPersId.Text, txtProCode.Text, username, pw));   
            Response.End();   
        }