/*
* variabeledeclaraties van de datechecker
*/

var dtCh= "-";
var minYear=1900;
var maxYear=2100;

/*
* onderstaande 2 functies worden gebruikt om 
* niet-datefuncties te checken en worden apart aangeroepen
*/
function checkValid(name){
        //alert(name);
        //alert(document.getElementById(name).value);
	var element = document.getElementById(name);
	if(element.selectedIndex!=0 && element.value!=""){
	 	element.style.backgroundColor='#BBFFBB';
	}else{
		element.style.backgroundColor='#FFFFFF';
	}
	if(countInvalid()){
		document.getElementById('insert').disabled=false;
	}
}

function countInvalid(){
	var iterator = 0;
	var checked = true;
	while(iterator < document.getElementById('form').elements.length){
		if(document.getElementById('form').elements[iterator].style.backgroundColor=='rgb(255, 255, 255)'||document.getElementById('form').elements[iterator].style.backgroundColor=='#ffffff'){
			checked = false;
		}
		iterator++;
	}
	return checked;
}

/*
* onderstaande functies worden gebruikt om 
* datefuncties te checken en worden door elkaar aangeroepen
* via de ValidateForm functie
*/

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 strYear=dtStr.substring(0,pos1)
	var strMonth=dtStr.substring(pos1+1,pos2)
	var strDay=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){
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		return false
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		return false
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		return false
	}
return true
}

function ValidateForm(name){
	var dt=document.getElementById(name);
	var form = document.getElementById("form").elements;
	var check = new Array();
	
	for(var i = 0; i<form.length; i++){
		var type = form[i].id.toLowerCase();
		if(i!=0)
		var type_before = form[i-1].id.toLowerCase();
		if(i!=form.length-1)
		var type_after = form[i+1].id.toLowerCase();
		if(type.match("date") != null){
			if(type_before.match("date") != null || type_after.match("date") != null)	
				check.push(i);
		}
	}
	
	if(isDate(form[check[0]].value) == true && isDate(form[check[1]].value) == true){
		date1 = new Date();
		date1.setMonth(form[check[0]].value.substr(5, 2));
		date1.setDate(form[check[0]].value.substr(8, 2));
		date1.setFullYear(form[check[0]].value.substr(0, 4));
		date2 = new Date();
		date2.setMonth(form[check[1]].value.substr(5, 2));
		date2.setDate(form[check[1]].value.substr(8, 2));
		date2.setFullYear(form[check[1]].value.substr(0, 4));
		if(date1 <= date2){
			form[check[0]].style.backgroundColor='#BBFFBB';
			form[check[1]].style.backgroundColor='#BBFFBB';
			if(countInvalid()){
				document.getElementById('insert').disabled=false;
			}
		}else{
			form[check[0]].style.backgroundColor='#FFFFFF';
			form[check[1]].style.backgroundColor='#FFFFFF';
		}
	}else{
		form[check[0]].style.backgroundColor='#FFFFFF';
		form[check[1]].style.backgroundColor='#FFFFFF';
	}
 }