function validateZipCode(mode){

	var inputField = 'tx_baywaadvisors_pi1_search_' + mode;
	var element = document.getElementById(inputField);

	switch (isInteger(element.value)){
         case true:
			return true;
			break;
         case false:
            alert('Bitte geben Sie eine gültige 5-stellige Postleitzahl ein.');
			return false;
	}

}

function isInteger (s){
      var i;
      if (isEmpty(s))
      if (isInteger.arguments.length == 1) return 0;
      else return (isInteger.arguments[1] == true);

      for (i = 0; i < s.length; i++)
      {
         var c = s.charAt(i);

         if (!isDigit(c)) return false;
      }

	  if(s.length < 5){
		return false;
	  }

	  return true;
}

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

function isDigit (c)
   {
      return ((c >= "0") && (c <= "9"))
   }