Date field validation

Dear all,
I am entering date data into a text input. I would like to validate the date entered. The date can be in the following formats.
dd/mm/yyyy
dd/mmm/yyyy
How does one do this validation through Javascript.
Code snippets for date validation would help a lot.
Thanks in advance.

this one forces date format: mm/dd/yyyy:

Code:

---

function isValidDate(myDate) {
  var datefmt = /(^\d{1,2})[\/]{1,1}(\d{1,2})[\/]{1,1}(\d{4,4}$)/;
  var result = myDate.match(datefmt);

  if ( result != null ) {
      var month = result[1];
      var date  = result[2];
      var year  = result[3];
      var test = new Date(year,month-1,date);
      //alert("result="+result);

      if (year == test.getFullYear() && (month-1 == test.getMonth()) && (date == test.getDate()))
        return true;
      else
        return false;
  }
  else
      return false;
}

---

Thanks fella. Thank you very much.