function validateEmail(inputfield) 
{
  var result = true;
  
  if(! document.getElementById(inputfield).value.match(/^[a-zA-Z0-9_\.-]{2,}@[a-z0-9-]{3,}\.[a-z]{2,4}$/))
  {
   alert("Die eMail-Adresse ist ungültig!");
   document.getElementById(inputfield).focus();
   result = false;
  }
  
  return result;
}

function validateURL(inputfield, mayBeEmpty) 
{
	var regexp = /(ftp|http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/
	var val = document.getElementById(inputfield).value;
  var valid = false;

  if (mayBeEmpty)
    valid = (val == "" || val == "http://" || regexp.test(val));
  else
    valid = regexp.test(val);
    
  if(!valid)
  {
   alert("Die URL ist ungültig.\nURLs für Webseiten müssen mit http:// anfangen.");
   document.getElementById(inputfield).focus();
  }
  
  return valid;
}

function validateFieldFilled(inputfield, fieldname)
{
  var result = true;
  
  if (document.getElementById(inputfield).value == "")
  {
    alert("Das Feld '" +fieldname+ "' darf nicht leer sein!");
    document.getElementById(inputfield).focus();
    result = false;
  }
  
  return result;
}

function validateDateField(inputfield, fieldname)
{
  var result = true;
  var content = document.getElementById(inputfield).value;
  
  if ((content.length != 10) || (content[2] != '.') || (content[5] != '.'))
  {
    alert("Für das Feld '" +fieldname+ "' bitte das Datumsformat DD.MM.YYYY verwenden!")
    document.getElementById(inputfield).focus();
    result = false;
  }
  
  return result;
}

function validateTimeField(inputfield, fieldname)
{
  var result = true;
  var content = document.getElementById(inputfield).value;
  
  if ((content.length != 5) || (content[2] != ':'))
  {
    alert("Für das Feld '" +fieldname+ "' bitte das Zeitformat HH:MM verwenden!")
    document.getElementById(inputfield).focus();
    result = false;
  }
  
  return result;
}