/**
 * DHTML date validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */
// Declaring valid date character, minimum year and maximum year
var dtCh = "/";
var minYear = 1900;
var maxYear = 2080;

function isInteger(s) {
    var i;
    for (i = 0; i < s.length; i++) {
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag) {
    var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++) {
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary(year) {
    // February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
    for (var i = 1; i <= n; i++) {
        this[i] = 31
        if (i == 4 || i == 6 || i == 9 || i == 11) {
            this[i] = 30
        }
        if (i == 2) {
            this[i] = 29
        }
    }
    return this
}


function isDate(dtStr) {
    var daysInMonth = DaysArray(12)
    var pos1 = dtStr.indexOf(dtCh)
    var pos2 = dtStr.indexOf(dtCh, pos1 + 1)
    var strMonth = dtStr.substring(0, pos1)
    var strDay = dtStr.substring(pos1 + 1, pos2)
    var strYear = dtStr.substring(pos2 + 1)
    strYr = strYear
    if (strDay.charAt(0) == "0" && strDay.length > 1) strDay = strDay.substring(1)
    if (strMonth.charAt(0) == "0" && strMonth.length > 1) strMonth = strMonth.substring(1)
    for (var i = 1; i <= 3; i++) {
        if (strYr.charAt(0) == "0" && strYr.length > 1) strYr = strYr.substring(1)
    }
    month = parseInt(strMonth)
    day = parseInt(strDay)
    year = parseInt(strYr)
    if (dtStr != '') {
        if (pos1 == -1 || pos2 == -1) {
            alert("The date format should be : mm/dd/yyyy")
            return false
        }
        if (strMonth.length < 1 || month < 1 || month > 12) {
            alert("Please enter a valid month")
            return false
        }
        if (strDay.length < 1 || day < 1 || day > 31 || (month == 2 && day > daysInFebruary(year)) || day > daysInMonth[month]) {
            alert("Please enter a valid day")
            return false
        }
        if (strYear.length != 4 || year == 0 || year < minYear || year > maxYear) {
            alert("Please enter a valid 4 digit year")
            return false
        }
        if (dtStr.indexOf(dtCh, pos2 + 1) != -1 || isInteger(stripCharsInBag(dtStr, dtCh)) == false) {
            alert("Please enter a valid date")
            return false
        }
    }
    return true
}

function validateDate(strDate) {
    var dt = strDate;
    if (dt) {
        isDate(dt);
    }
}