Please help! I am new to the webservice.
I have created a webservice , but my client can't call my webservice and receive this error : Server did not recognize the value of HTTP Header SOAPAction: .

Below is my webservice :

Code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Xml;
using System.IO;
...