function validateContent() {
  if (document.forms[0].fdUserName.value == '') {
    alert(webTerms[4]);
    document.forms[0].fdUserName.focus();
    return false;
  }
  if (document.forms[0].fdUserEmail.value == '') {
    alert(webTerms[5]);
    document.forms[0].fdUserEmail.focus();
    return false;
  }
  if (document.forms[0].fdMailtoName.value == '') {
    alert(webTerms[6]);
    document.forms[0].fdUserName.focus();
    return false;
  }
  if (document.forms[0].fdMailto.value == '') {
    alert(webTerms[7]);
    document.forms[0].fdUserEmail.focus();
    return false;
  }
  hideElementEx(document.getElementById('InputForm'));
  var el = getElementsByClass(document, 'button', 'input');
  for (var i=0; i<el.length; i++)
    hideElementEx(el[i]);
  showElementEx(document.getElementById('InputMessage'));
  return true;
}
function getElementsByClass(node, searchClass, tag) {
  var classElements = new Array();
  var els = node.getElementsByTagName(tag); // use "*" for all elements
  var elsLen = els.length;
  var pattern = new RegExp("\\b"+searchClass+"\\b");
  for (i = 0, j = 0; i < elsLen; i++) {
     if ( pattern.test(els[i].className) ) {
       classElements[j] = els[i];
       j++;
     }
  }
  return classElements;
}