Delphi7 quickly calls the web services implemented by C #

How to implement web services between different platforms? The following is the Web Services I use Delphi7 to call C:
(1) Create an Asp.net Web Service in vs2005. The system automatically generates a service that returns a string ("helloworld.
(2) Open Delphi7, create a new project, save the project, and then open file | new | Other | WebServices | wsdlimporter. Create a service and save it according to the steps. When adding a service, add? WSDL:

(3) Add the service name (such as service), button, text. Box, and (Web services) to the uses of unit1.pas, and set the properties of the control,

(4) write the button click event. The Code is as follows:

Procedure tform1.button1click (Sender: tobject );
VaR
A: servicesoap;
Begin
A: = Httprio1 As Servicesoap;
Edit1.text: = A. helloworld;
End;

(5) Now you can see that the string returned by the Service appears in text. Box.