//Устраняет проблему  2000 
function y2k(number)
{
   return (number <  1000 ) ? number +  1900  : number;
}
//Проверка валидности даты
function isDate(dd, mm, yyyy)
{
   xDate = new Date(yyyy, mm -  1 , dd);
   if(xDate.getDate() != dd || xDate.getMonth() +  1  != mm || y2k(xDate.getYear()) != yyyy)
      return false;
   else
      return true;
}
//Проверка даты рожедния
function check_birth()
{
   f_birth = document.getElementById("r_birth").value;
   if(f_birth == "")
   {
      return flase;
   }
   re = new RegExp("^((\\d{2}\.){2})(\\d{4})$", "gi");
   if(f_birth.search(re) <  0 )
   {
      return false;
   }
   arDate = f_birth.split(".");
   if (!isDate(arDate[ 0 ], arDate[ 1 ], arDate[ 2 ]))
   {
      return false;
   }
   return true;
}