var field2focus = null;
function checknumber(obj) {
    var x = obj.value

    x = x.replace(",", "");
    x = x.replace(",", "");
    x = x.replace(",", "");
    x = x.replace(",", "");
    x = x.replace(",", "");

    if (x == '') {
        return false;
    }

    var anum = /(^\d+$)|(^\d+\.\d{1,10}$)/

    if (anum.test(x)) {
        return true;
    }
    else {
        alert("Please input a valid number!")
        field2focus = obj;
        setTimeout('focusField()', 10);
        return false;
    }
}

function isIntegerOnly(obj) {
    var i;
    var s = obj.value;
    for (i = 0; i < s.length; i++) {
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) {
            alert("Please input a valid integer!")
            field2focus = obj;
            setTimeout('focusField()', 10);
            return false;
        }
    }
    // All characters are integers.
    return true;
}

function focusField() {
    if (field2focus) field2focus.focus();
}
function isAlphanumeric(s) {
    var i;

    if (isEmpty(s))
        if (isAlphanumeric.arguments.length == 1) return defaultEmptyOK;
        else return (isAlphanumeric.arguments[1] == true);

    for (i = 0; i < s.length; i++) {
        // Check that current character is number or letter.
        var c = s.charAt(i);

        if (!(isLetter(c) || isDigit(c)))
            return false;
    }

    // All characters are numbers or letters.
    return true;
}

function isYear(s) {
    if (isEmpty(s))
        if (isYear.arguments.length == 1) return defaultEmptyOK;
        else return (isYear.arguments[1] == true);
    if (!isNonnegativeInteger(s)) return false;
    return ((s.length == 2) || (s.length == 4));
}
function isIntegerInRange(s, a, b) {
    if (isEmpty(s))
        if (isIntegerInRange.arguments.length == 1) return defaultEmptyOK;
        else return (isIntegerInRange.arguments[1] == true);

    if (!isInteger(s, false)) return false;

    var num = parseInt(s);
    return ((num >= a) && (num <= b));
}
function isMonth(s) {
    if (isEmpty(s))
        if (isMonth.arguments.length == 1) return defaultEmptyOK;
        else return (isMonth.arguments[1] == true);
    return isIntegerInRange(s, 1, 12);
}
function isDay(s) {
    if (isEmpty(s))
        if (isDay.arguments.length == 1) return defaultEmptyOK;
        else return (isDay.arguments[1] == true);
    return isIntegerInRange(s, 1, 31);
}

// 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) {
    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 checkDateFormat(obj) {
    if (obj.value != "") {
        var result = isDate(obj.value);
        if (!result) {
            field2focus = obj;
            setTimeout('focusField()', 10);
            obj.focus();
        }
    }
}