posting phone number to another url and it response to me postal code

You need to read the documentation of the other web site to determine how to use the web site. Then if you need help, refer to the articles ini this web site. Then if you have specific questions, create a thread in the relevant forum in this web site. If this is an ASP application then the questions should be in the ASP forum. There are otehr forums that would be more appropriate than the C# Language forum for your question about ASP and/or the internet.