Date field validation

[msdnexpert]

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:

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;
}

[msdnexpert]

Thanks fella. Thank you very much.