var is_regexp = (window.RegExp) ? true : false;

var DOMtype = '';
if (document.getElementById)
{
	DOMtype = "std";
}
else if (document.all)
{
	DOMtype = "ie4";
}
else if (document.layers)
{
	DOMtype = "ns4";
}

var objects = new Array();

function fetch_object(idname, forcefetch)
{
	if (forcefetch || typeof(objects[idname]) == "undefined")
	{
		switch (DOMtype)
		{
			case "std":
			{
				objects[idname] = document.getElementById(idname);
			}
			break;
			
			case "ie4":
			{
				objects[idname] = document.all[idname];
			}
			break;
			
			case "ns4":
			{
				objects[idname] = document.layers[idname];
			}
			break;
		}
	}
	return objects[idname];
}

function toggle_collapse(objid)
{
	if (!is_regexp)
	{
		return false;
	}
	obj = fetch_object("collapseobj_" + objid);	
	img = fetch_object("collapseimg_" + objid);
	cel = fetch_object("collapsecel_" + objid);
	if (!obj)
	{
		if (img)
		{
			img.style.display = "none";
		}
		return false;
	}
	if (obj.style.display == "none")
	{
		obj.style.display = "";
		save_collapsed(objid, false);
		if (img)
		{
			img_re = new RegExp("_collapsed\\.png$");
			img.src = img.src.replace(img_re, '.png');
		}
		if (cel)
		{
			cel_re = new RegExp("^(thead|tcat)(_collapsed)$");
			cel.className = cel.className.replace(cel_re, '$1');
		}
	}
	else
	{
		obj.style.display = "none";
		save_collapsed(objid, true);
		if (img)
		{
			img_re = new RegExp("\\.png$");
			img.src = img.src.replace(img_re, '_collapsed.png');
		}
		if (cel)
		{
			cel_re = new RegExp("^(thead|tcat)$");
			cel.className = cel.className.replace(cel_re, '$1_collapsed');
		}
	}
	return false;
}

function save_collapsed(objid, addcollapsed)
{
	var collapsed = fetch_cookie("trefpuntmagic_collapse");
	var tmp = new Array();
	if (collapsed != null)
	{
		collapsed = collapsed.split("\n");
		for (i in collapsed)
		{
			if (collapsed[i] != objid && collapsed[i] != "")
			{
				tmp[tmp.length] = collapsed[i];
			}
		}
	}
	if (addcollapsed)
	{
		tmp[tmp.length] = objid;
	}
	expires = new Date();
	expires.setTime(expires.getTime() + (1000 * 86400 * 365));
	set_cookie("trefpuntmagic_collapse", tmp.join("\n"), expires);
}

function fetch_cookie(name)
{
	cookie_name = name + "=";
	cookie_length = document.cookie.length;
	cookie_begin = 0;
	while (cookie_begin < cookie_length)
	{
		value_begin = cookie_begin + cookie_name.length;
		if (document.cookie.substring(cookie_begin, value_begin) == cookie_name)
		{
			var value_end = document.cookie.indexOf (";", value_begin);
			if (value_end == -1)
			{
				value_end = cookie_length;
			}
			return unescape(document.cookie.substring(value_begin, value_end));
		}
		cookie_begin = document.cookie.indexOf(" ", cookie_begin) + 1;
		if (cookie_begin == 0)
		{
			break;
		}
	}
	return null;
}

function set_cookie(name, value, expires)
{
	if (!expires)
	{
		expires = new Date();
	}
	document.cookie = name + "=" + escape(value) + "; expires=" + expires.toGMTString() +  "; path=/";
}

function delete_cookie(name)
{
	var expireNow = new Date();
	document.cookie = name + "=" + "; expires=Thu, 01-Jan-70 00:00:01 GMT" +  "; path=/";
}