function validaData(pObj) {
  var expReg = /^((0[1-9]|[12]\d)\/(0[1-9]|1[0-2])|30\/(0[13-9]|1[0-2])|31\/(0[13578]|1[02]))\/(19|20)?\d{2}$/;
  var aRet = true;
  if ((pObj) && (pObj.value.match(expReg)) && (pObj.value != '')) {
    var dia = pObj.value.substring(0,2);
    var mes = pObj.value.substring(3,5);
    var ano = pObj.value.substring(6,10);
    if ((mes == 4 || mes == 6 || mes == 9 || mes == 11) && dia > 30) 
      aRet = false;
    else 
      if ((ano % 4) != 0 && mes == 2 && dia > 28) 
        aRet = false;
      else
        if ((ano%4) == 0 && mes == 2 && dia > 29)
          aRet = false;
  }  else 
    aRet = false;  
  return aRet;
}