XMLHttpRequest对象状态码为0

Question

I have a Javascript function using an XMLHttpRequest object, but the status I keep getting returned is 0. I've done lots of searching, and all I've come up with is that 0 is an undefined error and can be caused by a myriad of reasons. As such, I'm hoping you guys can spot the error in my code.

function initiateIPP(ID, Token)
    {
        var POSTRequest = new XMLHttpRequest();
        POSTRequest.onreadystatechange = function ()
        {
            if (POSTRequest.readyState == 4)
            {
                if (POSTRequest.status == 200)
                {

                }
                else
                {
                    alert("An error has occured, response code = " + POSTRequest.status);
                }
            }
        }
        var parameters = "SessionId=" + ID + "&SST=" + Token;
        POSTRequest.open("POST", "https://demo.ippayments.com.au/access/index.aspx", true)
        POSTRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded")
        POSTRequest.send(parameters)
        window.open("IPPPage.html");
    }

Thanks in advance.

EDIT: I added a withCredentials line to my code but that doesn't seem to have made a difference. var parameters = "SessionId=" + ID + "&SST=" + Token; POSTRequest.withCredentials = true; POSTRequest.open("POST", " https://demo.ippayments.com.au/access/index.aspx ", true) POSTRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded") POSTRequest.send(parameters) window.open("IPPPage.html");

Answer 1

" https://demo.ippayments.com.au/access/index.aspx " this should be same domain with your javascript, otherwise, you should set :

Access-Control-Allow-Origin: *

on target page's response header to get work. See http://enable-cors.org/

For example you can put below in web.config on target server :

<configuration>
 <system.webServer>
   <httpProtocol>
     <customHeaders>
       <add name="Access-Control-Allow-Origin" value="*" />
     </customHeaders>
   </httpProtocol>
 </system.webServer>
</configuration>

Answer 2

To integrated properly with the IPPayments page at https://demo.ippayments.com.au/access/index.aspx , you need to use the Direct Post method. Instead of using the XMLHttpRequest object, use a HTML form to submit the ID and token. For example -

<form action="https://demo.ippayments.com.au/access/index.aspx" method="post">
    <input type="hidden" name="SST" value="1243123123123123123"/>
    <input type="hidden" name="SessionID" value="53535434535345"/>
    <input type="submit" value="submit" />
</form>