function showFacebook(projekt_id, options) {	
	// creating page cover
	var cover = document.getElementById('facebook-cover');

	if(!cover) {
		var cover = document.createElement('div');
		cover.setAttribute('id', 'facebook-cover');
		cover.style.position = 'absolute';
		cover.style.top = 0;
		cover.style.left = 0;		
		cover.style.width = getDocWidth() + 'px';
		cover.style.height = getDocHeight() + 'px';
      cover.style.display = 'none';
		
		cover.show = function() {
			this.style.display = '';
			return this;
		}
		cover.hide = function() {
			this.style.display = 'none';
			return this;
		}		
		document.getElementsByTagName('body')[0].appendChild(cover);
	}
	
	
	//Ermittle Hoehe
	var yScroll;	
	if (window.innerHeight && window.scrollMaxY) {	
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		yScroll = document.body.scrollHeight;
	} else { 
      //Explorer Mac...wuerde auch in Explorer 6 Strict, Mozilla und Safari funktionieren
		yScroll = document.body.offsetHeight;
	}
	if(document.all || navigator.appName == "Opera"){
      yScroll = document.all.layout.offsetHeight;
    }

	var windowHeight;
	if (self.innerHeight) {
		//alle Browser ausser Internet Explorer
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { 
		//Internet Explorer 6  im Strict Modus
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { 
		//andere Internet Explorer
		windowHeight = document.body.clientHeight;
	}

   var DifHeight = yScroll - windowHeight;
   var finalHeight = parseInt(DifHeight) + 50;	
	

	// creating content area
	var content = document.getElementById('facebook-content');
   	
	if(!content) {
		if(facebook_lang == "de"){
            insert_fb_fan_1 = "Facebook: Fan werden!";
            insert_fb_fan_2 = "Werde Fan von";
            insert_auf_facebook = "auf Facebook!";
		} else{
            insert_fb_fan_1 = "Facebook: Become a Fan!";
            insert_fb_fan_2 = "Become a fan of ";
            insert_auf_facebook = "on Facebook!";		
		}
        var content = document.createElement('div');
		content.setAttribute('id', 'facebook-content');
		content.style.position = 'absolute';
		content.style.top = finalHeight + 'px';
		content.style.left = '100px';
		content.style.width = '940px';
		content.style.zIndex = 101;
		content.style.display = 'none';
		content.style.backgroundColor = 'white';
		content.style.padding = '5px 10px 10px 10px';
		content.style.MozBorderRadius = '4px';
		content.innerHTML = ''+
            '<div class="corners-top"></div>'+
            '<div class="facebook-cover">'+
            '<a href="#" onclick="document.getElementById(\'facebook-content\').hide();document.getElementById(\'facebook-cover\').hide(); return false;" class="facebook-close">X</a>'+
            '<h2 class="facebook-title">'+ insert_fb_fan_1 +'</h2>'+
            '<div id="facebook-canvas">'+
            '<iframe scrolling="no" frameborder="0" src="http://www.facebook.com/connect/connect.php?id=83538609419&connections=10&stream=1&css=http://www.dfg-science-tv.de/includes/styles.css" allowtransparency="true" style="border: none; width: 300px; height: 550px;"></iframe>'+
            '<div>' + insert_fb_fan_2 + ' <a href="http://www.facebook.com/pages/DFG-Science-TV/83538609419" style="color:#1299D9;">DFG Science TV</a> ' + insert_auf_facebook + '</div>'+
            '</div>'+      
            '</div>'+
            '<div class="corners-bottom"></div>';
			
		content.show = function() {
			var embeds = document.getElementsByTagName('embed');
			for(var i = 0; embeds[i]; i++) {
				embeds[i].style.display = 'none';
			}
			this.style.display = '';
			return this;
		}
		content.hide = function() {
			this.style.display = 'none';
			var embeds = document.getElementsByTagName('embed');
			for(var i = 0; embeds[i]; i++) {
				embeds[i].style.display = '';
			}
			return this;
		}
		
		document.getElementsByTagName('body')[0].appendChild(content);
	}
	
	// setup Facebook canvas
	var canvas = document.getElementById('facebook-canvas');
	if(!!canvas && options.width && options.height) {
		canvas.style.width = options.width+'px';
		canvas.style.height = options.height+'px';
	}
	
	// show layer
	cover.show(); 
	content.show();
}