testcl.js

var pageUrl = "http://something.com/gsm";
var interactionId = "email-form"; //id of the product

document.getElementsByClassName(interactionId).onsubmit = function AfterFunction(e){
	var xmlhttp;

    if (window.XMLHttpRequest) {
        // code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp = new XMLHttpRequest();
    } else {
        // code for IE6, IE5
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }

    xmlhttp.onreadystatechange = function() {
        if (xmlhttp.readyState == 4 ) {
           if(xmlhttp.status == 200){
           		alert(JSON.stringify(customform(document.getElementsByClassName(interactionId))));
               document.getElementById("myDiv").innerHTML = xmlhttp.responseText;
           }
           else if(xmlhttp.status == 400) {
              alert('There was an error 400')
           }
           else {
               alert('something else other than 200 was returned')
           }
        }
    }

	//alert(JSON.stringify(customform(document.getElementById(interactionId))));
}

function customform(form) {    
  var i, j, len, jLen, formElement, q = [];
  function addNameValue(name, value) {
      q.push(encodeURI(name) + '=' + encodeURI(value));
  }
  if (!form || !form.nodeName || form.nodeName.toLowerCase() !== 'form') {
      throw 'You must supply a form element';
  }
  for (i = 0, len = form.elements.length; i < len; i++) {
      formElement = form.elements[i];
      if (formElement.name === '' || formElement.disabled) {
          continue;
      }
      switch (formElement.nodeName.toLowerCase()) {
      case 'input':
          switch (formElement.type) {
          case 'text':
          case 'hidden':
          case 'password':
          case 'button': // Not submitted when submitting form manually, though jQuery does serialize this and it can be an HTML4 successful control
          case 'submit':
              addNameValue(formElement.name, formElement.value);
              break;
          case 'checkbox':
          case 'radio':
              if (formElement.checked) {
                  addNameValue(formElement.name, formElement.value);
              }
              break;
          case 'file':
              // addNameValue(formElement.name, formElement.value); // Will work and part of HTML4 "successful controls", but not used in jQuery
              break;
          case 'reset':
              break;
          }
          break;
      case 'textarea':
          addNameValue(formElement.name, formElement.value);
          break;
      case 'select':
          switch (formElement.type) {
          case 'select-one':
              addNameValue(formElement.name, formElement.value);
              break;
          case 'select-multiple':
              for (j = 0, jLen = formElement.options.length; j < jLen; j++) {
                  if (formElement.options[j].selected) {
                      addNameValue(formElement.name, formElement.options[j].value);
                  }
              }
              break;
          }
          break;
      case 'button': // jQuery does not submit these, though it is an HTML4 successful control
          switch (formElement.type) {
          case 'reset':
          case 'submit':
          case 'button':
              addNameValue(formElement.name, formElement.value);
              break;
          }
          break;
      }
  }
  return q.join('&');
}