function KeyDispatcher(sender, eventargs) {
    var handled = false;

    // Short cut key "T" for Today date
    if (eventargs._keyCode == 84 || eventargs._keyCode == 116) {
        sender.set_selectedDate(new Date());
        eventargs.set_cancel(true);
        handled = true;
    }

    // Short cut key "C" for Calendar control popup
    if (eventargs._keyCode == 99 || eventargs._keyCode == 67) {
        PopupAbove(sender, sender.Owner._validationInput.id);
        var element = sender.Owner._popupContainer;
        var firstLink = element.getElementsByTagName("a")[0];
        firstLink.focus();
        eventargs.set_cancel(true);
        handled = true;
    }
    
    // Allow Backspace, Tab and Delete keys
    if (eventargs._keyCode == 8 || eventargs._keyCode == 46 || eventargs._keyCode == 9) {
        eventargs.set_cancel(false);
        handled = true;
    }

    // Ignore anything other than shortcuts, numbers or '/'
    if (!handled) {
        if (eventargs._keyCode < 47 || eventargs._keyCode > 57) {
            eventargs.set_cancel(true);
            handled = true;
        }
    }

    if (handled) {
        eventargs.ReturnValue = false;
        if (eventargs.preventDefault)
            eventargs.preventDefault();
    }
}



/**
* 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 = 2100;

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) {
    2010 - 03 - 30
    03 - 30 - 2010

    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 (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 between " + minYear + " and " + maxYear);
        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 ValidateForm() {
    var dt = document.frmSample.txtDate;
    if (isDate(dt.value) == false) {
        dt.focus();
        return false;
    }
    return true;
}

function PopupAbove(e, pickerID) {
    var datePicker;
    datePicker = $find(pickerID);
    var textBox = datePicker.get_textBox();
    var popupElement = datePicker.get_popupContainer();
    var dimensions = datePicker.getElementDimensions(popupElement);
    var position = datePicker.getElementPosition(textBox);
    if (position.y - dimensions.height < 0) {
        datePicker.showPopup(position.x, position.y - 30);
    } else {
        datePicker.showPopup(position.x, position.y - dimensions.height);
    } 
}