var is_open = new Array();
var open_hoofding = new Array();
var open_titel = new Array();
var vol = 0;

function openTab(link, titel, hoofding, wiewat) {
	var laatste = 0;
	var item = "";
	var obj = "";
	var tab = "";
	
	for(var i = 1; i<=6;i++) {
		document.getElementById("item"+i).className = "non_active";
	}
	
	document.getElementById("overzicht").className = "non_active";
	if(!checkIfOpen(link)) {
		for(i=1;i<=6;i++) {
	        if (document.getElementById("item"+i).innerHTML.length == 0) {
			    laatste = i;
				i = 7;
		    } 
		}
		if (laatste == 0) {
		    if(vol < 6) {
	 		    vol++;
	 		}
	 		else {
	 		    vol = 1;
	 		}
	 		    laatste = vol;
	 		for(i = 1;i<=6;i++) {
	 		    document.getElementById("item"+i).className = "non_active";
	 		}	
		}
			tab = "item" + laatste;
			obj = document.getElementById(tab);
		
		for(i=1;i<laatste;i++) {
			document.getElementById("item"+i).className = "non_active";
		}
		
		document.getElementById("overzicht").className = "non_active";
		if(laatste == 0) {
		    item = "item6";
		}
		else { 
		    item = "item" + laatste;
		}
		var onclic = "onclick=\"activateTab('" + link + "', '" + item + "');return false;\"";
		if (wiewat == "wat")
		{
		    var onclose = "onclick=\"closeTab('" + laatste + "', 'wat');return false;\"";
		}else{
		    if (wiewat == "kost")
		    {
		        var onclose = "onclick=\"closeTab('" + laatste + "', 'kost');return false;\"";
		    }else{
		        var onclose = "onclick=\"closeTab('" + laatste + "');return false;\"";
		    }
		}
		var changeImage = "onmouseover=\"changeImages('close" +i+ "', 'img/close_over.png'); return true;\" onmouseout=\"changeImages('close" +i+ "', 'img/close.png'); return true;\" onmousedown=\"changeImages('close" +i+ "', 'img/close_over.png'); return true;\" onmouseup=\"changeImages('close" +i+ "', 'img/close.png'); return true;\"";	
		var content = "<a href=''><div class='tab_close'"+onclose+"><img src='img/close.png' alt='Sluiten' id='close"+i+"' name='close"+i+"'/></div></a><p><a href='#' title='"+ titel +"'" + onclic +">" + hoofding + "</a></p>";
		
		
		obj.style.visibility = "visible";
		obj.className = "active";
		obj.innerHTML = content;
		
		is_open[item] = link;
		open_hoofding[item] = hoofding;
		open_titel[item] = titel;
	
		processajax(link, 'tab_content', 'get', '');
	}
}

function closeTab(itemNr, wiewat) {
	itemNr = parseInt(itemNr);
	vol = 0;
	var item = "item" + itemNr;
	var nextItem = "item" + (itemNr +1);
	var prevItem = "item" + (itemNr -1);
	var last = false;
	var prevLink = is_open[prevItem];
	var nextLink = is_open[nextItem];
	
	if(itemNr != 6) {
		if(document.getElementById(nextItem).innerHTML.length == 0) {
			last = true;
		}
		
		//huidige tab leegmaken
		
		document.getElementById(item).className= "non_active";
		document.getElementById(item).style.visibility = "hidden";
		document.getElementById(item).innerHTML = "";
		
		is_open[item] = "";
		open_hoofding[item] = "";
		open_titel[item] = "";
		
		//redirect
		
		if(last) {
			if(itemNr == 1) {
				getOverzicht(wiewat);
			}
			else {
				activateTab(prevLink, prevItem);
			}		
		}
		else {
			var i = itemNr;
			i = parseInt(i);
			var next = i+1;
			
			
			while(next <= 6 && document.getElementById("item"+next).innerHTML.length != 0) {
				//alert("item" + next);
							
				link = is_open["item"+next];
				hoofding = open_hoofding["item"+next];
				titel = open_titel["item"+next]; 
				
				var onclic = "onclick=\"activateTab('" + link + "', 'item" + i + "');return false;\"";
		        if (wiewat == "wat")
		        {
				    var onclose = "onclick=\"closeTab('" + i + "', 'wat');return false;\"";
		        }else{
		            if (wiewat ==  "kost"){
		                var onclose = "onclick=\"closeTab('" + i + "', 'kost');return false;\"";
		            }else{
		                var onclose = "onclick=\"closeTab('" + i + "');return false;\"";
		            }
		        }
				var changeImage = "onmouseover=\"changeImages('close" +i+ "', 'img/close_over.png'); return true;\" onmouseout=\"changeImages('close" +i+ "', 'img/close.png'); return true;\" onmousedown=\"changeImages('close" +i+ "', 'img/close_over.png'); return true;\" onmouseup=\"changeImages('close" +i+ "', 'img/close.png'); return true;\"";	
				var content = "<a href=''><div class='tab_close'"+onclose+"><img src='img/close.png' alt='Sluiten' id='close"+i+"' name='close"+i+"'/></div></a><p><a href='#' title='"+ titel +"'" + onclic+">" + hoofding + "</a></p>";
				
				document.getElementById("item"+i).innerHTML = content;
				document.getElementById("item"+i).style.visibility = "visible";
				document.getElementById("item"+1).className="active";
				
				is_open["item"+i] = is_open["item"+next];
				open_hoofding["item"+i] = open_hoofding["item"+next];
				open_titel["item"+i] = open_titel["item"+next];
				
				document.getElementById("item"+next).innerHTML = "";
				document.getElementById("item"+next).style.visibility = "hidden";
				document.getElementById("item"+next).className = "non_active";
				
				is_open["item"+next] = "";
				open_hoofding["item"+next] = "";
				open_titel["item"+next] = "";
				
				i++;
				next++;
				activateTab(nextLink, nextItem, itemNr);
				
			}	
		}		
	}	
	else {
			document.getElementById(item).className= "non_active";
			document.getElementById(item).style.visibility = "hidden";
			document.getElementById(item).innerHTML = "";
		
			is_open[item] = "";
			open_hoofding[item] = "";
			open_titel[item] = "";
			
			activateTab(prevLink, "item5", 5);
		}
	}

function getOverzicht(testvar) {
	for(i=1;i<=6;i++) {
		document.getElementById("item"+i).className = "non_active";
	}
	
	document.getElementById("overzicht").className = "active";
	
	if (testvar == "wat"){
	    processajax('INC_overzicht.asp?qstr=wat', 'tab_content', 'get', '');
	}else{
	    if (testvar == "kost")
	    {
	        processajax('INC_overzicht.asp?qstr=kost', 'tab_content', 'get', '');
	    }else{
	        processajax('INC_overzicht.asp', 'tab_content', 'get', '');
	    }
	}
	
}

function activateTab(link, item, itemNr) {
	document.getElementById("overzicht").className = "non_active";
	for (i=1;i<=6;i++) {
		document.getElementById("item"+i).className= "non_active";
	}
	
	if(!itemNr) {
		document.getElementById(item).className = "active";
	}
	else {
		itemNr = parseInt(itemNr);
		document.getElementById("item"+itemNr).className= "active";
	}
	document.getElementById("overzicht").className = "non_active";
	processajax(link, 'tab_content', 'get', '');
}

function checkIfOpen(link) {
	for(i=1;i<=6;i++) {
		if(is_open["item"+i] == link) {
			var item = "item"+i;
			var alreadyOpen = true;
			activateTab(link, item);
			i = 7;
		}
		else {
			alreadyOpen = false;
		}
	}
	return alreadyOpen;
}