var ns4 = document.layers;
	var op5 = (navigator.userAgent.indexOf("Opera 5")!=-1) 
		||(navigator.userAgent.indexOf("Opera/5")!=-1);
	var op6 = (navigator.userAgent.indexOf("Opera 6")!=-1) 
		||(navigator.userAgent.indexOf("Opera/6")!=-1);
	var agt=navigator.userAgent.toLowerCase();
	var mac = (agt.indexOf("mac")!=-1);
	var ie = (agt.indexOf("msie") != -1); 
	var mac_ie = mac && ie;

function getElementHeight(Elem) {
	if (ns4) {
		var elem = getObjNN4(document, Elem);
		return elem.clip.height;
	} else {
		if(document.getElementById) {
			var elem = document.getElementById(Elem);
		} else if (document.all){
			var elem = document.all[Elem];
		}
		if (op5) { 
			xPos = elem.style.pixelHeight;
		} else {
			xPos = elem.offsetHeight;
		}
		return xPos;
	} 
}

function getElementWidth(Elem) {
	if (ns4) {
		var elem = getObjNN4(document, Elem);
		return elem.clip.width;
	} else {
		if(document.getElementById) {
			var elem = document.getElementById(Elem);
		} else if (document.all){
			var elem = document.all[Elem];
		}
		if (op5) {
			xPos = elem.style.pixelWidth;
		} else {
			xPos = elem.offsetWidth;
		}
		return xPos;
	}
}

		function strpos( haystack, needle, offset)
		{
    	var i = haystack.indexOf( needle, offset );
  	  return i >= 0 ? i : false;
		}

		function getImageWidth(myImage)
		{
			var x, obj;

			if (document.layers)
			{
				var img = getImage(myImage);
				return img.width;
			}
			else
			{
				return getElementWidth(myImage);
			}
			return -1;
		}

		function getImageHeight(myImage) {
			var y, obj;

			if (document.layers)
			{
				var img = getImage(myImage);
				return img.height;
			}
			else
			{
				return getElementHeight(myImage);
			}
			return -1;
		}

	function updateView(id) {
		
		var view = document.getElementById("view");
		var size = document.getElementById("size");
		var size_row = document.getElementById("size_row");
		var spacer = document.getElementById("spacer");
		
		var picdiv = document.getElementById('picdiv');
		
		if(view.value > 0) {
			size_row.style.display = '';
			spacer.style.display = 'none';
		}else{
			size_row.style.display = 'none';
			spacer.style.display = '';		
		}
		
		var url = 'ajax.php?preview,' + id + ',' + view.value + ',' + size.value;		
		var ai = new AJAXInteraction('html','views', url , function(type, target, responseText) {
			
			document.getElementById(target).innerHTML = responseText;
		});
		ai.doGet();	
	}
	
function AJAXInteraction(type, target, url, callback) { 
 
    var req = init(); 
    var response = null; 
    req.onreadystatechange = processRequest; 
 
    function init() { 
      if (window.XMLHttpRequest) { 
        return new XMLHttpRequest(); 
      } else if (window.ActiveXObject) { 
        return new ActiveXObject("Microsoft.XMLHTTP"); 
      } 
    } 
 
    function processRequest () { 
      if (req.readyState == 4) { 
        if (req.status == 200) { 
            if (type == 'html') { 
                response = req.responseText; 
            } 
            if (type == 'xml'){ 
                response = req.responseXML; 
            } 
            if (typeof callback == "string") {
            	window[callback](type, target, response); 
            }else{
            	callback(type, target, response); 
            }
        } 
      } 
    } 
 
    this.doGet = function() { 
      req.open("GET", url, true); 
      req.send(null); 
    } 
 
    this.doPost = function(body) { 
      req.open("POST", url, true); 
      req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); 
      req.send(body); 
    } 
} 	

	function check(targets) {
		
		var target = targets.split(",");
		
		var result = true;
		var message = "";
		
		for(var i=0;i<target.length;i++) {
			var elem = document.getElementById(target[i]);
			if(elem.value == "") {
				result = false;
				message = message + "Fehler:" + elem.name.substring(0,1).toUpperCase() + elem.name.substring(1,elem.name.length) + " muss ausgefüllt werden.\n\n"
			}
		}
		if(result) {
			return true;
		}else{
			alert(message);
			return false;
		}
	}