/* Contains:
   checkDate(s);
   cleanString(s);
   isNumeric(s);
   noneChecked(boxes);
   trim(s);
*/
// 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 strDay   = dtStr.substring(0,pos1);
	var strMonth = 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(dtStr+" is not a valid date.\nThe expected date format is : dd/mm/yyyy");
		return false;
	}
	if (strMonth.length<1 || month<1 || month>12){
		alert(dtStr+" is not a valid date.\nPlease enter a valid month");
		return false;
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert(dtStr+" is not a valid date.\nPlease enter a valid day");
		return false;
	}
	if (strYear.length != 4 || year==0 /*|| year<minYear || year>maxYear*/){
		//alert(dtStr+" is not a valid date.\nPlease enter a valid 4 digit year between "+minYear+" and "+maxYear);
		alert(dtStr+" is not a valid date.\nPlease enter a valid 4 digit year");
		return false;
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		alert(dtStr+" is not a valid date.\nPlease enter a valid date");
		return false;
	}
	return true;
}

function checkDate(s){
	if (!defined(s)) return '';
	
	s = trim(s);
	s = s.replace(/\-/g, '/');
	
	if (s == '')                         return '';
	if (s.toLowerCase() == 'dd/mm/yyyy') return '';
	if (!isDate(s))                      return '';
	/*if (s.indexOf("/") == -1)            return '';
	
	var arr = s.split("/");
	var i = 0;
	do{
		if (!isNumeric(arr[i])){ s = ''; break; }
		i++;
	} while (i < arr.length);
	*/
	return s;
}

function cleanString(s){
	s = s.replace(/\!/gi, '');
	s = s.replace(/\"/gi, '');
	s = s.replace(/\#/gi, '');
	//s = s.replace(/\%/gi, '');
	s = s.replace(/\&/gi, '');
	s = s.replace(/\'/gi, ' ');
	s = s.replace(/\(/gi, '');
	s = s.replace(/\)/gi, '');
	s = s.replace(/\*/gi, '');
	s = s.replace(/\+/gi, '');
	s = s.replace(/\,/gi, '');
	s = s.replace(/\./gi, '');
	s = s.replace(/\:/gi, '');
	s = s.replace(/\;/gi, '');
	s = s.replace(/\</gi, '');
	s = s.replace(/\=/gi, '');
	s = s.replace(/\>/gi, '');
	s = s.replace(/\?/gi, '');
	s = s.replace(/\\/gi, '');
	s = s.replace(/\^/gi, '');
	s = s.replace(/\_/gi, ' ');
	s = s.replace(/\`/gi, '');
	s = s.replace(/\|/gi, '');
	s = s.replace(/\~/gi, '');
	s = s.replace(/\s+/g, ' ');		//any space character (\n,\r,\t)
	return trim(s);
}

function isNumeric(s){
	var nums = "0123456789";
	var is_num = true;
	var c, i = 0;
	
	if (!defined(s)) return false;
	
	s = trim(s);
	if (s == '') return false;
	
	do{
		c = s.charAt(i);
		if (nums.indexOf(c) == -1){ is_num = false; break; }
		i++;
	} while (i < s.length);
	
	return is_num;
}

function noneChecked(boxes){
	if (boxes.checked) return false;
	
	var i=0, no_check=true;
	while (i<boxes.length && no_check){
		if (boxes[i].checked == true) no_check = false;
		i++;
	}
	return no_check;
}

function trim(s){
	s = s.replace(/^\s+/g, '');    //strip leading
	return s.replace(/\s+$/g, ''); //strip trailing
}