two iframes

HTML

<p id="data"></p>

<!--update the src of this iframe to the HTPURL you obtained from the https://test-htp.tokenex.com/api/v1 call -->
<iframe id="tokenExIframe1" width="30%" height="20%" scrolling="no" frameborder="0" src="https://test-htp.tokenex.com/iframe/v2/gVoFuexvtD5KKBzjlralBYBUY6ZusB4g0MkHdEbi"></iframe>
<br/>

<iframe id="tokenExIframe2" width="30%" height="20%" scrolling="no" frameborder="0" src="https://test-htp.tokenex.com/iframe/v2/3ff5a4f4655e4743983d9b89db6391cb"></iframe>

<button type="button" id="bthTokenize1">Tokenize1</button>
<button type="button" id="bthTokenize2">Tokenize2</button>

JavaScript

document.getElementById('bthTokenize1').onclick = tokenize1;
document.getElementById('bthTokenize2').onclick = tokenize2;

var iframe1 = document.getElementById("tokenExIframe1");
var iframe2 = document.getElementById("tokenExIframe2");

//add event listener for postmessage
if (window.addEventListener) {
  addEventListener("message", listener, false)
} else {
  attachEvent("onmessage", listener)
}


function tokenize1() {
  iframe1.contentWindow.postMessage('tokenize', 'https://test-htp.tokenex.com');
}
function tokenize2() {
  iframe2.contentWindow.postMessage('tokenize', 'https://test-htp.tokenex.com');
}

//handle the message from the iframe
function listener(event) {
  if (event.origin === 'https://test-htp.tokenex.com') {
    var message = JSON.parse(event.data);
    switch (message.event) {
      case 'focus':
        if (message.data.value) {
          //field has focus
        } else {
          //field does not have focus(blur)
        }
      case 'change':
        // field changed
        break;
      case 'validation':
        if (!message.data.isValid) {
          //field failed validation
        } else {
          //validation valid!
        }
        break;
      case 'post':
        if (!message.data.success) {
          // use message.data.error 
        } else {
          //get token! message.data.token
        }
        break;
    }
    log("iframe message:" + event.data)

  } else {
    log("Oops! Origin: " + event.origin + " isn't allowed")
  }
}

function log(message) {
  document.getElementById("data").innerHTML += '<em>'+ message+ '</em>' + "<br /><br />";
}