var req = null;

function ajax_request2(url,http_request_send,dowhat)
{
	try{
		req = new XMLHttpRequest();
	}
	
    catch (ms){
    	try{
        	req = new ActiveXObject("Msxml2.XMLHTTP");
		} 
        catch (nonms){
        	try{
            	req = new ActiveXObject("Microsoft.XMLHTTP");
			} 
            catch (failed){
            	req = null;
			}
		}  
	}

	if (req == null)
		alert("Error creating request object!");
                  
	//anfrage erstellen (POST, url ,
	//request ist asynchron      
	req.open("POST", url, true);

	//Beim abschliessen des request wird diese Funktion ausgeführt
	req.onreadystatechange = function(){            
	switch(req.readyState) {
    	case 4:
			if(req.status!=200) {
				alert("Fehler:"+req.status); 
			}else{    
				if(typeof dowhat == 'function') dowhat()
			}
            break;
                    
            default:
            	return false;
			break;     
		}
	};
  
	req.setRequestHeader("Content-Type",
		"application/x-www-form-urlencoded");
	req.send(http_request_send);
}

function load_page(page, target)
{			 	
	var url = "load_page.php";
	
	var http_request_send = 'page='+escape(page);
    	
	var return_function = function(){
		if(req.responseText == "extern")
		{
			window.open(page);
			return false;
		}
		document.getElementById(target).innerHTML=req.responseText;
		for(var i = 0;i < document.getElementsByTagName('a').length; i++)
		{
			document.getElementsByTagName('a')[i].onclick = link_clicked;
		}
		
	};
	ajax_request2(url,http_request_send,return_function);
	return false;
}

function link_clicked(Ereigniss)
{
	if(!ajax_support
	|| this.href.substring(7, 18) != document.URL.substring(7,18))
	{
		return true;
	}
	load_page(this.href,'content_left');
	return false;
}

var ajax_support = null;

try{
	req = new XMLHttpRequest();
}

catch (ms){
	try{
    	req = new ActiveXObject("Msxml2.XMLHTTP");
	} 
    catch (nonms){
    	try{
        	req = new ActiveXObject("Microsoft.XMLHTTP");
		} 
        catch (failed){
        	req = null;
		}
	}  
}

if (req == null)
	ajax_support = false;
else
	ajax_support = true;