function Right(str, n){
    if (n <= 0)
       return "";
    else if (n > String(str).length)
       return str;
    else {
       var iLen = String(str).length;
       return String(str).substring(iLen, iLen - n);
    }
}

function ValidateDate(d1,d2,m1,m2,dest,lang){
    Vdag=document.getElementById(d1).value;
	Vtemp=document.getElementById(m1).value;
	Vmonthyear = Vtemp.split("/");
	Rdag=document.getElementById(d2).value;
	Rtemp=document.getElementById(m2).value;
	Rmonthyear=Rtemp.split("/");
	var tempDes = document.getElementById(dest).value;
	var Vdate = Vmonthyear[1] + Vmonthyear[0] + Vdag;
	var Rdate = Rmonthyear[1] + Rmonthyear[0] + Rdag;
	
	if (parseFloat(Rdate) < parseFloat(Vdate)) {
		switch(lang){
			
			case 'nl':
				alert("Gelieve de retourdatum na te kijken!");
				break;
			case 'fr':       
				alert("Veuillez vérifier la date de retour!");
				break;
			default:
				alert("Please check the return date!");
				break;
		}
		return false;
	}else{
    	if (tempDes == ""){			
						
			switch(lang){
			
				case 'nl':
					alert("Gelieve een bestemming in te vullen.");
					break;
				case 'fr':       
					alert("Veuillez remplir la destination.");
					break;
				default:
					alert("Please fill in the destination.");
					break;
			}
			return false;
		}else{
			switch(window.location.hostname){
				
				case "www.biac.be":
					window.open('/biac/popframe.asp','biacpopup','width=850,height=600,toolbar=no,scrollbars=no');
					break;
					
				default:
					break;
					
			}			
    		return true;
        }
    }
}

function changeRetDay(d1,d2){

	intSelectedDay = document.getElementById(d1).options.selectedIndex;	
	intDays = document.getElementById(d1).options.length;
	
	if(intSelectedDay + 7 >= intDays){
		 document.getElementById(d2).options.selectedIndex = intSelectedDay + 7 - intDays;
	}
	else{
		document.getElementById(d2).options.selectedIndex = intSelectedDay + 7;
	}	
}

function changeRetDate(d1,d2,m1,m2){	

	if (document.getElementById(d2).options.selectedIndex < document.getElementById(d1).options.selectedIndex) {
		document.getElementById(m2).selectedIndex = document.getElementById(m1).selectedIndex+1;
		CreateDayList(d2,m2);
	}
	else{	
		document.getElementById(m2).selectedIndex = document.getElementById(m1).selectedIndex;	
		CreateDayList(d2,m2);	
	}
}

function addNewOption(fld,val,txt) {
	//alert("fld= "+fld+"\nval= "+val+"\ntxt= "+txt);
	var no = new Option();
	no.value = val;
	no.text = txt;
	fld.options[fld.options.length] = no;
}

function CreateMonthList(lst,interval){

   // Maak vertrekmaand + jaar drop down aan (deze maand + 12)
   
   var d = new Date();

	var curr_date = d.getDay();
	var dep_Month = parseInt(d.getMonth())+1;	
	var dep_Year = d.getFullYear();

	j = dep_Month + interval;
	i = dep_Month;
	
	while (i < j){
		dep_Month2 = "" + dep_Month;
		if (dep_Month2.length < 2){
			depDateValue = "0";
		}
		else{
			depDateValue = "";
		}
		depDateValue = depDateValue + dep_Month + "/" + dep_Year;
		
		addNewOption(document.getElementById(lst), depDateValue, aryMonths[dep_Month] + " " + dep_Year);		
		
		if (dep_Month == 12){
			dep_Month = 1;
			dep_Year = dep_Year + 1;
		}
		else{
			dep_Month = dep_Month + 1;
		}
		i = i + 1;
	}
	//if (curr_date<=7) {
		//alert(curr_date);
		//document.getElementById(lst).options.selectedIndex = 1;
	//} else {
		document.getElementById(lst).options.selectedIndex = 0;
	//}
}

function CreateDayList(lstDay,lstMonth){
	
	/* get which month & year from the dropdown */
	
	intSelectedDay = document.getElementById(lstDay).options.selectedIndex;
	if (intSelectedDay<0){intSelectedDay=0};
	intSelectedValue = document.getElementById(lstMonth).options[document.getElementById(lstMonth).options.selectedIndex].value;
	intSelectedMonth = eval(intSelectedValue.substr(0,2)-1);
	intSelectedYear = intSelectedValue.substr(3,4);
	
	/* clear dropdrown */
	document.getElementById(lstDay).length = 0;
		
	/* create dateobject with these values and set the day to the first */
	objDate = new Date(intSelectedYear, intSelectedMonth,1);
	
	/* iterate until the month changes */ 
	do {
		
		/* add an option with the weekday and day */
		strOptionText = "0" + objDate.getDate();
		strOptionValue =  "0" + objDate.getDate();
		strOptionText = aryWeekDay[objDate.getDay()] + " " + Right(strOptionText,2);	
		strOptionValue = Right(strOptionValue,2);
		addNewOption(document.getElementById(lstDay),strOptionValue,strOptionText);
				
		/* add 1 day  */
		objDate.setDate(objDate.getDate()+1);	
			
		
	/* end iteration */
	} while (objDate.getMonth()==intSelectedMonth);
	document.getElementById(lstDay).options.selectedIndex = intSelectedDay;
}

function initList(d1,d2,m1,m2, interval){

	CreateMonthList(m1,12);
	CreateMonthList(m2,18);
	
	objToday = new Date();
	
	i = parseInt(objToday.getMonth());
	objToday.setDate(objToday.getDate() + interval);
	j = parseInt(objToday.getMonth());
	
	if (j>i) {
		document.getElementById(m1).options.selectedIndex = document.getElementById(m2).options.selectedIndex + 1;
	}
	CreateDayList(d1,m1);
	document.getElementById(d1).options.selectedIndex = parseInt(objToday.getDate())-1;
	
	objToday = new Date();
	i = parseInt(objToday.getMonth());
	objToday.setDate(objToday.getDate() + interval + 7);
	j = parseInt(objToday.getMonth());
	
	if (i>j) {
		document.getElementById(m2).options.selectedIndex = document.getElementById(m2).options.selectedIndex + 1;
	}
	CreateDayList(d2,m2);
	document.getElementById(d2).options.selectedIndex = parseInt(objToday.getDate())-1;
	changeRetDate(d1,d2,m1,m2);
}

function Querystring(qs) { // optionally pass a querystring to parse
	this.params = new Object()
	this.get=Querystring_get
	
	if (qs == null)
		qs=location.search.substring(1,location.search.length)

	if (qs.length == 0) return

// Turn <plus> back to <space>
// See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
	qs = qs.replace(/\+/g, ' ')
	var args = qs.split('&') // parse out name/value pairs separated via &
	
// split out each name=value pair
	for (var i=0;i<args.length;i++) {
		var value;
		var pair = args[i].split('=')
		var name = unescape(pair[0])

		if (pair.length == 2)
			value = unescape(pair[1])
		else
			value = name
		
		this.params[name] = value
	}
}

function Querystring_get(key, default_) {
	// This silly looking line changes UNDEFINED to NULL
	if (default_ == null) default_ = null;
	
	var value=this.params[key]
	if (value==null) value=default_;
	
	return value
}