function IsDateValid(year, month, day)
{
//  Source http://javascript.internet.com/forms/validate-date.html?testdat=29.01.2008&button=Press+to+Validate
    
    var err = 0;
    var leap = 0;

//    /* Validation of year */

    if(year == "" || day == "" || month == "")
    {
        err = 1;
    }
    /* Validation of year */

    else if (year == 0) {
      err = 20;
    }

    else if(year > 2100 || year < 1900)
    {
        err = 1;
    }

    /* Validation of month*/
    else if ((month < 1) || (month > 12)) {
        err = 21;
    }
    /* Validation of day*/

    else if (day < 1) {
        err = 22;
    }

    /* Validation leap-year / february / day */
    if ((year % 4 == 0) || (year % 100 == 0) || (year % 400 == 0))
    {
        leap = 1;
    }
    else
    {
        leap = 0;
    }

    if ((month == "2") && (leap == 1) && (day > 29)) {
      err = 23;
    }

    else if ((month == "2") && (leap != 1) && (day > 28)) {
      err = 24;
    }

    /* Validation of other months */
    else if ((day > 31) && ((month == "1") || (month == "3") || (month == "5") || (month == "7") || (month == "8") || (month == "10") || (month == "12"))) {
      err = 25;
    }

    else if ((day > 30) && ((month == "4") || (month == "6") || (month == "9") || (month == "11"))) {
      err = 26;
    }

    return (err == 0);
}


function IsTimeValid(hour, minute)
{
    
    if((hour >= 0 && hour <= 23) && (minute >= 0 && minute < 60))
        return true;
    return false;
    
}