function BT_Physics(inF){
    return 0.5*(1+Math.sin(-0.5*Math.PI+inF*Math.PI));
}

//
// PopUp
//

var gImageW=0;
var gImageH=0;
var gImageURL="";
var gYouTubeCode="";
var gNickname="";
var gPopUpTime=0;
var gIntervalFunction=0;

function BT_ArtistPopUp(inNickname){
    gImageW=640;
    gImageH=330;
	gImageURL="";
    gYouTubeCode="";
	gNickname=inNickname;
    BT_PopUp();
}

function BT_ScreenshotPopUp(inW,inH,inImage){
	gImageW=inW;
	gImageH=inH;
	gImageURL=inImage;
    gYouTubeCode="";
	gNickname="";
    BT_PopUp();
}

function BT_YouTubePopUp(inW,inH,inYouTubeCode){
	gImageW=inW;
	gImageH=inH;
	gImageURL="";
    gYouTubeCode=inYouTubeCode;
	gNickname="";
    BT_PopUp();
}

function BT_PopUp(){

    BT_ClosePopUp();

	var cw=document.documentElement.clientWidth;
	var ch=document.documentElement.clientHeight;
	
	var xo=window.pageXOffset;
	var yo=window.pageYOffset;

	var w=0;
	var h=0;

	var xc=xo+(cw-w)/2;
	var yc=yo+(ch-h)/2;	
	
	e=document.createElement("div");
	e.id			="MyPopUp0";
	e.innerHTML	    ="";
	e.style.left	=xo+"px";
	e.style.top	    =yo+"px";
	e.style.width	=cw+"px";
	e.style.height	=ch+"px";
	e.onclick		=BT_ClosePopUp;	
	$(e).css({opacity:0});
	$('body').append(e);

	e=document.createElement("div");
	e.id			="MyPopUp1";
	e.innerHTML		="";
	e.style.left	=xc+"px";
	e.style.top		=yc+"px";
	e.style.width	=w+"px";
	e.style.height	=h+"px";
	if(gYouTubeCode.length<=0) e.onclick=BT_ClosePopUp;	
	$('body').append(e);	

	var d = new Date();
 	gPopUpTime=d.getTime();

	gIntervalFunction=setInterval('BT_Update()',10);

	return false;	//href doet op deze manier niets
}

function BT_ClosePopUp(){
	$('#MyPopUp0').remove();
	$('#MyPopUp1').remove();
	$('#MyPopUp2').remove();
}

function BT_Update(){

	var e=document.getElementById("MyPopUp1");
	if(!e) return;

	var w=e.style.width;
	w=w.replace("px","");
	w=Number(w);

	if(w>=gImageW) return;

	var d = new Date();
 	w=(1.0*(d.getTime()-gPopUpTime))/300;
	if(w<0) w=0;
	if(w>1) w=1;
	w=w*w;
	
	
	var k=w*0.5;
    $("#MyPopUp0").css({opacity:k});	
	
	
	w*=gImageW;
	if(w>gImageW) w=gImageW;

	var h=(w*gImageH)/gImageW;	

	var cw=document.documentElement.clientWidth;
	var ch=document.documentElement.clientHeight;

	var xc=(cw-w)/2;
	var yc=(ch-h)/2;

	xc+=window.pageXOffset;
	yc+=window.pageYOffset;

	e.style.left  = xc+"px";
	e.style.top   = yc+"px";
	e.style.width = w+"px";
	e.style.height= h+"px";

	if(w==gImageW){   	
	    if(gNickname.length>0){
    		e.innerHTML="<iframe id='MyPopUpiFrame' width='"+gImageW+"' height='"+gImageH+"' scrolling='no' ></iframe>";
	    }
	    else if(gImageURL.length>0){
    		e.innerHTML="<img src='"+gImageURL+"' />";
    	}    	
    	else if(gYouTubeCode.length>0){
           	e.innerHTML="<object width='"+gImageW+"' height='"+gImageH+"'><param name='movie' value='http://www.youtube.com/v/"+gYouTubeCode+"&amp;hl=en&amp;color1=0x3a3a3a&amp;color2=0x999999'></param><param name='wmode' value='transparent'></param><param name='allowfullscreen' value='true'></param><embed src='http://www.youtube.com/v/"+gYouTubeCode+"&amp;hl=en&amp;color1=0x3a3a3a&amp;color2=0x999999' type='application/x-shockwave-flash' wmode='transparent' width='"+gImageW+"' height='"+gImageH+"' allowfullscreen='true'></embed></object>";
    	}
    	
        //Als je dit bovenin in de innerHTML meteen meegeeft
        //gaat het mis als je op de back knop van de browser klikt
        //hij blijft dan steeds dezelfde artist tonen
	    if(gNickname.length>0){
            $("#MyPopUpiFrame").attr("src","artistinfo.php?Artist="+gNickname);
        }
        
        
        //Close button
        var r1=12;	
        var r2=16;  //r1/sin(45)
	    e=document.createElement("div");
	    e.id			    ="MyPopUp2";
	    e.innerHTML		    ="<a title='Close this popup' href='javascript:BT_ClosePopUp()'>X</a>";
	    e.style.left		=xc+w-r2+2*r1+"px";
	    e.style.top		    =yc-r2+"px";
    	$('body').append(e);   	
    	
    	
    	clearInterval(gIntervalFunction);
    	gIntervalFunction=0;
	}
}

//
// Contact Form
//

function BT_Join(){
	var e = document.getElementById('myform');
	if(!e) return;

	e = document.getElementById('EMAIL');
	if(!e) return;

	var email = e.value;
	if(email.length<=0 || email.indexOf('@')<=0 || email.indexOf('.')<=0){
		alert('Please enter a valid e-mail address');
		return;
	}
	document.getElementById('myform').submit();
}

//
// SlideShow
//
var gSlideShow_Pics         =10;
var gSlideShow_StaticTime   =4000;
var gSlideShow_FadeTime     =1000;

var gSlideShow_Index        =0;
var gSlideShow_TimeStart    =0;

function BT_Slideshow_Update(){
    if($("#slideshow1").length<=0) return;
    if($("#slideshow2").length<=0) return;

	var d = new Date();
 	var dt=d.getTime()-gSlideShow_TimeStart;
 
    if(dt<gSlideShow_StaticTime){
    }
    else if(dt<(gSlideShow_StaticTime+gSlideShow_FadeTime)){
        var O=1.0-(dt-gSlideShow_StaticTime)/gSlideShow_FadeTime;      
        O=BT_Physics(O);     

		$("#slideshow2").css({opacity:O});
    }
    else{
        gSlideShow_Index++;
        if(gSlideShow_Index>=gSlideShow_Pics) gSlideShow_Index=0;
 
		var i=gSlideShow_Index+1;
		if(i>=gSlideShow_Pics) i=0;
		
        $("#slideshow2").attr("src", "images/outerspace/screenshot"+(gSlideShow_Index+1)+".png");
		$("#slideshow2").css({opacity:1.0});
        $("#slideshow1").css("background-image", "url(images/outerspace/screenshot"+(i+1)+".png)");
		
	    var d = new Date();
 	    gSlideShow_TimeStart=d.getTime(); 	
    }
}

//
// OnLoad
//
	
window.onload = function () {

    //prevent our site from running in a frame:
    if(top.location != self.location){
       top.location.replace(self.location);
    }

    //remove the annoying little box around links 
    $("a").focus(function(){ $(this).blur(); });
	
	//prevent join and unsubscribe to be selected at the same time
    $('#JOIN').click(function(){
        if($("#JOIN").attr("checked")) $("#UNSUBSCRIBE").attr("checked",false);
    });
	
    $('#UNSUBSCRIBE').click(function(){
        if($("#UNSUBSCRIBE").attr("checked")) $("#JOIN").attr("checked",false);
    });		
	
	//start slideshow if present
	if($("#slideshow1").length>0 && $("#slideshow2").length>0){
	    var d = new Date();
 	    gSlideShow_TimeStart=d.getTime(); 	
    	setInterval('BT_Slideshow_Update()',10)
    }    
}