Hi..when i am trying to execute the code..its giving the following error:
'PublicServices.GetSignature(string, string)': not all code paths return a value.
the code is:

[WebMethod]
    public string GetSignature(string AccessKeyID, string content)
    {
        try
        {
            if (AuthorizeUser(AccessKeyID) == false)
            {
                return "";
            }
            Encoding myEncoding = new UTF8Encoding();
            // Create a new Cryptography class using the
            // Secret Access Key as the key
            HMACSHA1 myCrypto = new HMACSHA1(myEncoding.GetBytes(mySecretAccessKeyId)) ;
            // Calculate the digest
            byte[] strDigest = myCrypto.ComputeHash(Convert.FromBase64String(cont ent));
            return Convert.ToBase64String(strDigest);
        }
        catch (Exception ex)
        {
            sendException(ex);

        }
    }

public void sendException(Exception ex)
    {
       SendMail("[email protected]", "[email protected]", "errorhandling", "error occured" + ex.StackTrace + "\r\n" + "\r\n" + "error description :" + ex.Message.ToString() + "\r\n" + "\r\n" + "error generated time :" + System.DateTime.Now);
    }
public bool SendMail(string from, string to, string subject, string body)
    {
        try
        {
            SmtpClient mailObj = new SmtpClient();
            mailObj.Host = "mail.retgdsg.com";
            MailMessage msg = new MailMessage(from, to, subject, body);
            msg.IsBodyHtml = false;
            mailObj.Send(msg);
            return true;
        }
        catch (Exception ex)
        {
            return false;
        }
    }

could any one help me...in this regard.

The error means what it says - Not all code paths return a value.

If an exception is thrown inside the try/catch, then the execution will pass to the catch part of the code. From here to the end of the function there is no return statement. You either want to return null, or rethrow the exception.

/- Sam Judson : Wrox Technical Editor -/