function openChatWindow(channel,lang){

  if (typeof(channel)=='undefined'){
      alert('Channel not defined!');
          return;
	    }
	        
	      if (typeof(lang)=='undefined')
	          var lang  = '';
		      
		    if (typeof(chatWindow)=='undefined')
		        chatWindow  = false;
			 
			  var height  = 430;
			    var width   = 600;
			     
			      var params  = "status=no,toolbar=no,menubar=no,location=no,resizable=yes,scrollbars=no"; 
			       
			        params += ",height=" + height + ",innerHeight=" + height;
				  params += ",width=" + width + ",innerWidth=" + width;
				    
				    if (window.screen) {
				        var ah = screen.availHeight - 30;
					    var aw = screen.availWidth - 10;
					        var xc = (aw - width) / 2;
						    var yc = (ah - height) / 2;
						        params += ",left=" + xc + ",screenX=" + xc;
							    params += ",top=" + yc + ",screenY=" + yc;
							      }
							       
							        if (!chatWindow || (chatWindow && chatWindow.closed))
								    chatWindow = window.open("http://chat.fethard.biz/browsertest.php?channel="+channel+"&lang="+lang,'chat_'+String(Math.round(Math.random()*10000)),params);
								        
								      chatWindow.focus();
								        
 }