Ajax on Captive Network Assistant on iOS and OSX

Does ajax work on Captive network Assistant on iOS and OSX? I am using jquery to do the following but doesn't work. responseText variable is neither true nor false. Works great with the corresponding Safari browser as well as for Android and Windows devices.

Also, is there any documentation available for the Captive network Assistant ? I cannot google it.

function checkEmailHost(hostname) {

    if ($.ajax({
        type : "GET",
        url : "welcome/emailvalidate",
        data : "hostname=" + hostname,
        async : false
    }).responseText == "true") {
        return true;
    } else {
        return false;
    }


}

      

        
        
        
      

    

Thanks in advance.