//adsfuncs.js

//function list
//*********************************************************
//ltrim(s) - removes whitespace from beginning of a string
//rtim(s) - removes whitespace from end of a string
//trim(s) - removes whitespace form beginning and end of a string
//checkValidDate(dateStr) - validates date
//isnumbetween(s, min, max) - checks that a number is between min and max
//islenbetween(s, min, max) - checks that the length of a string is between min and max
//isbetween(s, min, max) - checks that s is beteen min and max (length or amount)
//*********************************************************

//removes whitspace from beginning of a string
function ltrim (s) {
	return s.replace( /^\s*/, "" );
}

//removes whitspace from end of a string
function rtrim (s) {
	return s.replace( /\s*$/, "" );
}

//removes whitspace from beginning and end of a string
function trim (s) {
	return rtrim(ltrim(s));
}

//makes sure a string is a valid date
function checkValidDate(dateStr) {
    // dateStr must be of format month day year with either slashes
    // or dashes separating the parts. Some minor changes would have
    // to be made to use day month year or another format.
    // This function returns True if the date is valid.
    var slash1 = dateStr.indexOf("/");
    if (slash1 == -1) { slash1 = dateStr.indexOf("-"); }
    // if no slashes or dashes, invalid date
    if (slash1 == -1) { return false; }
    var dateMonth = dateStr.substring(0, slash1)
    var dateMonthAndYear = dateStr.substring(slash1+1, dateStr.length);
    var slash2 = dateMonthAndYear.indexOf("/");
    if (slash2 == -1) { slash2 = dateMonthAndYear.indexOf("-"); }
    // if not a second slash or dash, invalid date
    if (slash2 == -1) { return false; }
    var dateDay = dateMonthAndYear.substring(0, slash2);
    var dateYear = dateMonthAndYear.substring(slash2+1, dateMonthAndYear.length);
    if ( (dateMonth == "") || (dateDay == "") || (dateYear == "") ) { return false; }
    // if any non-digits in the month, invalid date
    for (var x=0; x < dateMonth.length; x++) {
        var digit = dateMonth.substring(x, x+1);
        if ((digit < "0") || (digit > "9")) { return false; }
    }
    // convert the text month to a number
    var numMonth = 0;
    for (var x=0; x < dateMonth.length; x++) {
        digit = dateMonth.substring(x, x+1);
        numMonth *= 10;
        numMonth += parseInt(digit);
    }
    if ((numMonth <= 0) || (numMonth > 12)) { return false; }
    // if any non-digits in the day, invalid date
    for (var x=0; x < dateDay.length; x++) {
        digit = dateDay.substring(x, x+1);
        if ((digit < "0") || (digit > "9")) { return false; }
    }
    // convert the text day to a number
    var numDay = 0;
    for (var x=0; x < dateDay.length; x++) {
        digit = dateDay.substring(x, x+1);
        numDay *= 10;
        numDay += parseInt(digit);
    }
    if ((numDay <= 0) || (numDay > 31)) { return false; }
    // February can't be greater than 29 (leap year calculation comes later)
    if ((numMonth == 2) && (numDay > 29)) { return false; }
    // check for months with only 30 days
    if ((numMonth == 4) || (numMonth == 6) || (numMonth == 9) || (numMonth == 11)) { 
        if (numDay > 30) { return false; } 
    }
    // if any non-digits in the year, invalid date
    for (var x=0; x < dateYear.length; x++) {
        digit = dateYear.substring(x, x+1);
        if ((digit < "0") || (digit > "9")) { return false; }
    }
    // convert the text year to a number
    var numYear = 0;
    for (var x=0; x < dateYear.length; x++) {
        digit = dateYear.substring(x, x+1);
        numYear *= 10;
        numYear += parseInt(digit);
    }
    // Year must be a 2-digit year or a 4-digit year
    if ( (dateYear.length != 2) && (dateYear.length != 4) ) { return false; }
    // if 2-digit year, use 50 as a pivot date
    if ( (numYear < 50) && (dateYear.length == 2) ) { numYear += 2000; }
    if ( (numYear < 100) && (dateYear.length == 2) ) { numYear += 1900; }
    if ((numYear <= 0) || (numYear > 9999)) { return false; }
    // check for leap year if the month and day is Feb 29
    if ((numMonth == 2) && (numDay == 29)) {
        var div4 = numYear % 4;
        var div100 = numYear % 100;
        var div400 = numYear % 400;
        // if not divisible by 4, then not a leap year so Feb 29 is invalid
        if (div4 != 0) { return false; }
        // at this point, year is divisible by 4. So if year is divisible by
        // 100 and not 400, then it's not a leap year so Feb 29 is invalid
        if ((div100 == 0) && (div400 != 0)) { return false; }
    }
    // date is valid
    return true;
}

//checks to see if a number is between min and max
function isnumbetween (s, min, max) {
	return ( ( s >= ( min != null ? min : Number.MIN_VALUE ) )
		&&  ( s <= ( max != null ? max : Number.MAX_VALUE ) ) );
}

//checks to see if a string length is between min and max
function islenbetween (s, min, max) {
	return ( ( s.length >= ( min != null ? min : 0 ) )
		&&  ( s.length <= ( max != null ? max : Number.MAX_VALUE ) ) );
}

//checks to make sure that a variable is between the min and max
function isbetween (s, min, max) {
	if ( isNaN ( s ) )
		return islenbetween ( s, min, max );
	else
		return isnumbetween ( s, min, max );
}

//validates email address
function checkEmail(sEmailAddress) {
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(sEmailAddress)) 
	  return true
	else 
	  return false;
}