var form = "";
var submitted = false;
var error = false;
var error_message = "";

function validateRequired(field){
if (form.elements[field].checked == false){
error = true;
}
}
function check_form(form_name) {
  error = false;
  form = form_name;
  error_message = "Please Accept the terms & Conditions.";
  validateRequired("acceptterms");
  if (error == true) {
    alert(error_message);
    document.shippingform.comments.focus()
    return false;
  } else {
    submitted = true;
    return true;
  }
}

function ValidateCheckout(){
if (check_form(document.getElementById("shippingform"))){
continueCheckout();
}
}