// handle the visibility of the navigation area
	function showDiv(divId)
	{
		if (!document.getElementById) {
			return null;
		}

		_hideDiv(document.getElementById("menuDiv"));
		_hideDiv(document.getElementById("searchDiv"));
		_hideDiv(document.getElementById("loginDiv"));
		_hideDiv(document.getElementById("helpDiv"));
		
		_showDiv(document.getElementById(divId));
	}
	// private function: handle the visibility of the navigation area	
	function _hideDiv(element)
	{
		if (element != null)
		{
			element.style.display = "none";
			document.getElementById('tablink_' + element.id.replace('Div','')).className = "";
		}
	}
	// private function: handle the visibility of the navigation area		
	function _showDiv(element)
	{
		if (element != null)
		{
			element.style.display = "block";
			document.getElementById('tablink_' + element.id.replace('Div','')).className = "selected";
		}
	}
	// add links to the horizontal navigation bar
	function generateLinks(linkId)
	{
		if (!document.getElementById) 
		{
			return null;
		}

		_generateLinks(document.getElementById("tablink_menu"));
		_generateLinks(document.getElementById("tablink_search"));
		_generateLinks(document.getElementById("tablink_login"));
		_generateLinks(document.getElementById("tablink_help"));
	}
	// private function: add links to the horizontal navigation bar
	function _generateLinks(element)
	{
		if (element != null)
		{
			var href = element.href;
			href = "javascript:showDiv('" + element.id.substring(8) + "Div');";
			element.setAttribute("href",href);
		}
	}
	// disable/disable form fields for period
	function manageSearchForm()
	{
		var checkbox = document.getElementById("periode");
		if (checkbox == null)
			return

		if (checkbox.checked)
		{
			var element = document.getElementById("fieldPeriode");
			if (element != null)
				element.style.color = "#25668a";
			
			element = document.getElementById("startdate");
			if (element != null)
				element.disabled=false;
				
			element = document.getElementById("enddate");
			if (element != null)
				element.disabled=false;
		}
		else
		{
			var element = document.getElementById("fieldPeriode");
			if (element != null)
				element.style.color = "#aaa";
			
			element = document.getElementById("startdate");
			if (element != null)
				element.disabled=true;
				
			element = document.getElementById("enddate");
			if (element != null)
				element.disabled=true;
		}
	}
	
	// insert text into textarea
	function jsinput(starttag,endtag)
	{
		// Internet Explorer
		if (document.selection) 
		{
			var formelement = document.getElementById("editform");
			selectedText = document.selection.createRange().text;
			document.selection.createRange().text = starttag + selectedText + endtag;
		}
		// Mozilla
		else if (document.forms['editform'].text.selectionStart || document.forms['editform'].text.selectionStart == "0") 
		{
			var formelement = document.forms['editform'].text;
			var startPos = formelement.selectionStart;
			var endPos = formelement.selectionEnd;
			var scrollTop = formelement.scrollTop;
			var sel = formelement.value;
			var selectedText = sel.substring(startPos, endPos);
			formelement.value = sel.substring(0, startPos) + starttag + selectedText + endtag + sel.substring(endPos, sel.length);
			
			formelement.focus();
			var cursorPos = startPos + (starttag.length + selectedText.length + endtag.length);
			formelement.selectionStart=cursorPos;
			formelement.selectionEnd=cursorPos;
			formelement.scrollTop=scrollTop;
		}
		else
		{
			formelement.value += chaineAj;
		}
		return;
	}

	// show or hide layers for textedit
	function toggleBox(szDivID, iState) // 1 visible, 0 hidden
	{
		if(document.layers)	 //NN4+
		{
			if (document.layers[szDivID])
			{
				document.layers[szDivID].visibility = iState ? "show" : "hide";
				document.layers[szDivID].display = iState ? "block" : "none";
			}
		}
		else if(document.getElementById)	//gecko(NN6) + IE 5+
		{
			var obj = document.getElementById(szDivID);
			if (obj)
			{
				obj.style.visibility = iState ? "visible" : "hidden";
				obj.style.display = iState ? "block" : "none";
			}
		}
		else if(document.all)	// IE 4
		{
			if (document.all[szDivID])
			{
				document.all[szDivID].style.visibility = iState ? "visible" : "hidden";
				document.all[szDivID].style.display = iState ? "block" : "none";
			}
		}
	}
	function externalLinks() 
	{ 
		if (!document.getElementsByTagName) 
			return;
		var anchors = document.getElementsByTagName("a"); 
		for (var i=0; i<anchors.length; i++) 
		{ 
			var anchor = anchors[i]; 
			if (anchor.getAttribute("href"))
			{
				var x=window.location.href.split('/'); 
				x.length=3;
				var str = x.join('/');
				
				if (anchor.href.substring(0, 7) == "http://" && 
					anchor.href.substring(0, str.length) != str)
				{
					anchor.target = "_blank"; 

					if (anchor.className == "")
					{
						anchor.className = "extern";
					}
				}
			}
		} 
	} 
	window.onload = function()
	{
		showDiv("menuDiv");
		generateLinks("tablink_menu");
		manageSearchForm();
		externalLinks();
	}