function openImage(imageUrl, imageWidth, imageHeight, imageAlt){
	var thisUrl = imageUrl;
	var thisWidth = imageWidth;
	var thisHeight = imageHeight;
	var thisAlt = imageAlt;
	
	var image = document.getElementById('myImage');
	image.setAttribute('src', thisUrl);
	image.setAttribute('alt', thisAlt);
	
	var imageContainer = document.getElementById('myImageContainer');
	try{
	imageContainer.removeChild(document.getElementById('myImageText'));
	}
	catch(err)
	{}
	var closeImage = document.getElementById('closeMyImage');
	closeImage.style.margin = (thisHeight+10) + "px 0px 0px "+ (thisWidth-20) + "px";
	imageContainer.style.width = (thisWidth+10)+"px";
	imageContainer.style.height = (thisHeight+50)+"px";
	imageContainer.style.margin = (-thisHeight/2) + "px 0px 0px " + (-thisWidth/2) + "px";
	var myText = document.createElement('div');
	thisAlt = thisAlt.split('<br/>');
	for(var i=0; i<thisAlt.length; i++){
		myText.appendChild(document.createTextNode(thisAlt[i]));
		myText.appendChild(document.createElement('br'));
	}
	myText.id = 'myImageText';
	imageContainer.appendChild(myText);
	imageContainer.style.display = "block";
	return null;
}

function closeImage(){
	var imageContainer = document.getElementById('myImageContainer');
	var image = document.getElementById('myImage');
	image.setAttribute('src', 'http://www.sg-grossdrebnitz.de/picz/icons/dummy.gif');
	image.setAttribute('alt', '');
	imageContainer.style.display = "none";
	return null;
}