function checkforblanks() {
    var errormessage = new String();
    for (var i = 0; i < arguments.length; i += 2) {
      if ((!arguments[i]) || (arguments[i] == "your@email.com")) {
        alert("Please enter " + arguments[i+1] + ".");
        return false;
      }
    }
	
	if(!WithoutCheck(document.form.Call_Back)) {
	  if(WithoutContent(document.form.phone.value)) {
	    errormessage += "You have asked to be contacted by phone but have not provided a telephone number.";
	  }
	}
	  
	if(errormessage.length > 2) {
	  alert('NOTE: ' + errormessage);
	  return false;
	}

    return true;
  }

  function WithoutContent(ss) {
    if(ss.length > 0) { return false; }
    return true;
  }

  function WithoutCheck(ss) {
    if(ss.checked) { return false; }
    return true;
  }


  function validate() {
    var isFull = checkforblanks(document.form.name.value, "your name", document.form.email.value, "a valid email address");
    if (!isFull) {
      return false;
    }
  }