Hi,the .NET Framework 1.1 defines a new protocol that is named HttpPostLocalhost. By default, this new protocol is enabled. This protocol permits invoking Web services that use HTTP POST requests from applications on the same computer. This is true provided the POST URL uses http://localhost, not http://hostname. This permits Web service developers to use the HTML-based test form to invoke the Web service from the same computer where the Web service resides.
When you try to access the Web service from a remote computer you do not see the Invoke button. And, you receive the following error message:
The test form is only available for requests from the local machine
You can enable these protocols for all Web services on the computer by editing the section in Machine.config. The following example enables HTTP GET, HTTP POST, and also SOAP and HTTP POST from localhost:
Code Snippet
<protocols>
<add name="HttpSoap"/>
<add name="HttpPost"/>
<add name="HttpGet"/>
<add name="HttpPostLocalhost"/>
<!-- Documentation enables the documentation/test pages -->
<add name="Documentation"/>
</protocols>
For more information ,please check this
artilce form msdn.