function in_array(needle, haystack, strict) {
    // http://kevin.vanzonneveld.net
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // *     example 1: in_array('van', ['Kevin', 'van', 'Zonneveld']);
    // *     returns 1: true
 
    var found = false, key, strict = !!strict;
 
    for (key in haystack) {
        if ((strict && haystack[key] === needle) || (!strict && haystack[key] == needle)) {
            found = true;
            break;
        }
    }
 
    return found;
}

var active_work_nrs = new Array();
var downloaded_work_nrs = new Array();

function distractFocus()
{
	//document.getElementById('dummyfocus').focus();
}

function showDiv(div_id)
{
	var div = document.getElementById(div_id);
	div.style.display = 'block';
}

function hideDiv(div_id)
{
	var div = document.getElementById(div_id);
	div.style.display = 'none';
}

function ajaxGetWorkData(work_nr)
{ 
	var xhr; 
	try
	{
		xhr = new ActiveXObject('Msxml2.XMLHTTP');
	}
	catch (e) 
	{
		try
		{
			xhr = new ActiveXObject('Microsoft.XMLHTTP');
		}
		catch (e2) 
		{
			try
			{
				xhr = new XMLHttpRequest();
			}
			catch (e3)
			{
				xhr = false;
			}
		}
	}
  
	xhr.onreadystatechange  = function()
	{ 
		if(xhr.readyState == 4)
		{
			if(xhr.status  == 200)
			{
				var doc = xhr.responseXML;   // Assign the XML file to a var
				divdata = doc.getElementsByTagName('divdata')[0].childNodes[0].nodeValue;
				div_id = 'w' + work_nr + '_info';

				document.getElementById(div_id).innerHTML = divdata;
				showDiv(div_id);
				active_work_nrs[active_work_nrs.length] = work_nr;
				downloaded_work_nrs[downloaded_work_nrs.length] = work_nr;
			}
			else 
			{
				alert("Error communicating with server!");
			}
		}
	}; 
	
	xhr.open('GET', 'get_work_data.php?work_id=' + work_nr, true); 
	xhr.send(null);
} 

function hideInfo(work_nr)
{
	distractFocus();
	var div_id = 'w' + work_nr + '_info';
	hideDiv(div_id);
	temp_arr = new Array();
	for (i=0; i<active_work_nrs.length; i++)
		if (active_work_nrs[i] != work_nr)
			temp_arr[temp_arr.length] = active_work_nrs[i];
			
	active_work_nrs = temp_arr;
}

function showInfo(work_nr)
{
	var div_id = 'w' + work_nr + '_info';

	if (!in_array(work_nr, active_work_nrs))
	{
		distractFocus();
		//if (active_work_nr != 0)
		//	hideInfo(active_work_nr);
		
		if (in_array(work_nr, downloaded_work_nrs))
		{
			showDiv(div_id);
			active_work_nrs[active_work_nrs.length] = work_nr;
		}
		else
			ajaxGetWorkData(work_nr);
	}
	else
		hideInfo(work_nr);
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}