How to add Access-Control-Allow-Origin?

Question

I am getting the following error when I call my webservice method.

Origin http://localhost:4165 is not allowed by Access-Control-Allow-Origin.

When referring net I am getting solution like add Access-Control-Allow-Origin I dont know where to add this. My script is :

 $(document).ready(function () {
        $.ajax({
            type: "Post", dataType: "json", contentType: "application/json; charset=utf-8",
            url: "http://localhost:63384/ListWebService.asmx/HelloWorld", success: function (data) { alert(data.d); }, error: function (request, status, error) {
                alert(request.responseText);
            }
        });
    });

And my webservice method is :

[WebMethod]
    public string HelloWorld()
    {
        return "Hello User";
    }

Solution

I have found the answer for my question. Just add the following to your web.config file

<system.webServer>
    <httpProtocol>
        <customHeaders>
            <add name="Access-Control-Allow-Origin" value="*"/>
            <add name="Access-Control-Allow-Headers" value="Origin, X-Requested-With, Content-Type, Accept" />
        </customHeaders>
    </httpProtocol>
</system.webServer>

Also if you dont want it to be set up globally, then you can add it to your action method alone as below:

[WebMethod]
public string HelloWorld()
{
    HttpContext.Response.Headers.Add("Access-Control-Allow-Origin", "*");
    return "Hello User";
}