// JavaScript Document

// OVERLAY

function showOverlay(){
	document.getElementById('overlay_container').style.visibility="visible";
}

function closeOverlay(){
	document.getElementById('overlay_container').style.visibility="hidden";
	document.getElementById('music_player').style.visibility="hidden";
	document.getElementById('music_player').style.display="none";
}

// AJAX

var xmlhttp;
function loadXMLDoc(url,get){
	xmlhttp=null;
	if(window.XMLHttpRequest){
  		xmlhttp=new XMLHttpRequest();
	}else{
  		xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  	}
	xmlhttp.onreadystatechange=eval(get);
	xmlhttp.open("GET",url,true);
	xmlhttp.send(null);
	// Switch background
	var page=url.substr(12,2);
	switch(page){
		case 'gr':
		document.getElementById('content_right').style.backgroundImage="url('images/content_bg_right_gear.jpg')";
		break;
		default:
		document.getElementById('content_right').style.backgroundImage="url('images/content_bg_right.jpg')";
		break;
	}
}

function getText(){
	if(xmlhttp.readyState==4){
  		if (xmlhttp.status==200){
    		document.getElementById('overlay_text').innerHTML=xmlhttp.responseText;
    	}else{
    		alert("Problem retrieving data:" + xmlhttp.statusText);
    	}
  	}
}

var http_request=false;
function makePOSTRequest(url,parameters){
	http_request=false;
	if(window.XMLHttpRequest){ // Mozilla, Safari,...
		http_request=new XMLHttpRequest();
        if(http_request.overrideMimeType){
            http_request.overrideMimeType('text/html');
        }
      }else if(window.ActiveXObject){ // IE
         try {
            http_request=new ActiveXObject("Msxml2.XMLHTTP");
         } catch(e) {
            try{
               http_request=new ActiveXObject("Microsoft.XMLHTTP");
            } catch(e) {}
         }
      }
      if(!http_request){
         alert('Cannot create XMLHTTP instance');
         return false;
      }
      http_request.onreadystatechange=alertContents;
      http_request.open('POST',url,true);
      http_request.setRequestHeader("Content-type","application/x-www-form-urlencoded");
      http_request.setRequestHeader("Content-length",parameters.length);
      http_request.setRequestHeader("Connection","close");
      http_request.send(parameters);
}

function alertContents() {
      if(http_request.readyState == 4){
         if(http_request.status == 200){
            //alert(http_request.responseText);
            result = http_request.responseText;
            document.getElementById('overlay_text').innerHTML = result;            
        }else{
        	alert('There was a problem with the request.');
		}
	}
}

var post_string="";
function toPOSTString(obj,url){
	var post_elements=obj.elements;
	for(i=0;i<post_elements.length;i++){
		post_string+="&"+post_elements[i].name+"="+escape(encodeURI(post_elements[i].value));
	}
	var poststr=post_string.substr(1);
	makePOSTRequest(url,poststr);
}


// FORMHANDLER

var elements=new Array();
var i=0;
var invalid=false;
function checkForm(form_name,form_elements){
	if(form_elements!=''){
		check_elements=form_elements.split('_');
		for(i=0;i<check_elements.length;i++){
			if(document.getElementById(form_name).elements[check_elements[i]].value==''){
				invalid=true;
				i=i+check_elements.length;
			}
		}
	}
	if(invalid==false){
		document.getElementById(form_name).submit();
	}
}

// MUSIC

function showPlayer(){
	document.getElementById('music_player').style.visibility="visible";
	document.getElementById('music_player').style.display="";
}

function hidePlayer(){
	document.getElementById('music_player').style.visibility="hidden";
	document.getElementById('music_player').style.display="none";
}

// SCROLLER

var scrollStep=1
var timerUp=""
var timerDown=""
function scrollDivDown(){
	clearTimeout(timerDown) 
	document.getElementById('text').scrollTop+=scrollStep
	timerDown=setTimeout("scrollDivDown('text')",10)
}

function scrollDivUp(div){
	clearTimeout(timerUp)
	document.getElementById('text').scrollTop-=scrollStep
	timerUp=setTimeout("scrollDivUp('text')",10)
}

function stopMe(){
	clearTimeout(timerDown) 
	clearTimeout(timerUp)
}