var whitespace = " \\t\\n\\r";
	var legalChars = "abcdefghijklmnopqrstuvwxyz0123456789_-."

	function isEmpty(s) { return ((s == null) || (s.length == 0)) }

	function isWhitespace (s) {
	  var i;
	  if (isEmpty(s)) return true;
	  for (i = 0; i < s.length; i++) {
	    var c = s.charAt(i);
	    if (whitespace.indexOf(c) == -1) return false;
	  }
	  return true;
	}
	
	function isEmail(s) {
	  if (isWhitespace(s)) {
		return false;
	  }
	  var sLength = s.length;
	  if (sLength < 6) return false;
	  var i = 0;
	  while ((i < sLength) && (s.charAt(i) != "@")) {
		if (legalChars.indexOf (s.charAt(i)) == -1) return false;
		i++;
	  }
	  if ((i < 2) || (i > (sLength - 3)) || (s.charAt(i) != "@")) {
		return false;
	  }
	  Index = i;
	  i++;
	  while ((i < sLength) && (s.charAt(i) != ".")) {
		if (legalChars.indexOf (s.charAt(i)) == -1) return false;
		i++;
	  }
	  if ((i < (Index + 3)) || (i >= sLength - 2) || (s.charAt(i) != ".")) {
		return false;
	  }
	  while (i < sLength) {
		if (legalChars.indexOf (s.charAt(i)) == -1) return false;
		i++;
	  }
	  return true;
	}
	
	function checkform() {
	  var message = ""; // create error message string variable, with nothing in it
      // Get all the forms
      var forms = document.getElementsByTagName('form');
      // Loop through the forms
      for(var i = 0, form; form = forms[i]; i++) {
        // Loop through the elements on each form
	    for(var j = 0; j < form.elements.length; j++) {
	      //alert('Element=>' + j + ' className=>' + form.elements[j].className);
		  // Check whether the element has a CSS class of 'required'
	      if(/required/.test(form.elements[j].className)) {
		  	  if (isEmpty(form.elements[j].value)) {
				  message = message + "- " + form.elements[j].name + " may not be blank.\n";
			  }
          }
        }
        // If the form has an element named 'email' check that it is valid
        if (!(isEmail(form.email.value))) {
          message = message + "- Your email is not valid.\n";
        }
	  }
	  if ( message.length > 0 ) { // is there an error message?
		message = "Please fill the form completely:\n\n" + message ;
		alert( message ); // display error message
		return false; // return bad, not ok to process
	  } else {
		//alert( "Thank you for your message." );
	    return true; // no error message to display, return ok to process
	  }
	} // end of the function checkform()