window.onload = initPage;

function initPage() {
  addFieldVal('name', 'Name');
  addFieldVal('company', 'Company');
  addFieldVal('email', 'Email');
  addFieldVal('tel', 'Tel');
  addFieldVal('message', 'Enquiry');
}

function addFieldVal(element, val) {
  if(document.getElementById(element)) {
    document.getElementById(element).onfocus = function () {clearfield(this, val);};
    document.getElementById(element).onblur = function () {reinstatefield(this, val);};
  }
}

function clearfield(element, val) {
  trimValue = trim(element.value);
  if(trimValue == val) {
    element.value = '';
  }
}

function reinstatefield(element, val) {
  trimValue = trim(element.value);
  if(trimValue == '') {
    element.value = val;
  }
}

function trim(str, chars) {
  var replaceLeft, replaceRight;
  chars = chars || "\\s";
  replaceLeft = str.replace(new RegExp("^[" + chars + "]+", "g"), "");
  replaceRight = replaceLeft.replace(new RegExp("[" + chars + "]+$", "g"), "");
  return replaceRight;
}