function DateValidate(source, arguments) {
    arguments.IsValid = isDate(arguments.Value, usrDateFormat);
}

function DateCompareValidate(source, arguments) {
    //   1 if date1 is greater than date2
    //   0 if date1 and date2 are the same
    //   2 if date1 is smaller than date2
    //  -1 if either of the dates is in an invalid format
    var txtDateFrom = document.getElementById(dateFromId);
    var retval = compareDates(txtDateFrom.value, usrDateFormat, arguments.Value, usrDateFormat);
    if (retval == 2 || retval == 0)
        arguments.IsValid = true;
    else
        arguments.IsValid = false;
}