I want to validate BirthDate, which should be in mm/dd/yyyy format, on the client side.

I have tried it as following, but it is not working properly:

$(#btnUpdateEditCB3).click(function(event) {

    var txtBirthDate = $('#<%= txtBirthDateCB3.ClientID %>').val();

    var txtNickName = $('#<%= txtNickNameCB3.ClientID %>').val();

    if (txtBirthDate != ) {

        if (txtBirthDate.match(/^(?:(0[1-9]1[012])[/.](0[1-9][12][0-9]3[01])[/.](1920)[0-9]{2})$/)) {

            alert(Please enter date in mm/dd/yyyy format);

            $('#<%= txtBirthDateCB3.ClientID %>').focus();

            return false;

        }

    }

});