var current_screen;
var halfcamera = 95;
var polzunok_offset;
var screen_size;


function LayerMover(instance,layer_name) {

	this.instance_name = instance;
	this.lrstl = document.getElementById(layer_name).style;
	this.norm_posx = 0;
	this.norm_posxmax = 1;
	this.timeframe = 2000;//millisec
	this.steps=50;
	this.lock = 0;
	this.run = function(delta,offset) {
		if (this.lock==1) return;
		this.lock = 1;
		
		this.delta = Math.abs(delta);
		this.offset = offset;
		this.distance = -1*this.delta;
		this.time_increment = this.timeframe/this.steps;
		this.dist_increment = this.norm_posxmax/this.steps
		this.dist_increment = this.distance/this.steps;
		this.positionx = this.delta;
		this.finish = 0;
		this.positiony = 0;
		this.direction = (delta>0) ? 1 : -1;
		this.moveit();
	};

	this.moveit = function() {
		this.positiony = Math.easeInBounce(this.positionx, 0, Math.abs(this.distance), Math.abs(this.distance));
		this.positionx+=this.dist_increment;

		if (this.direction > 0) this.lrstl.left = this.positiony + this.offset + 'px';
		if (this.direction < 0) this.lrstl.left = this.delta-this.positiony + this.offset + 'px';
	
		if (this.positionx>this.finish && this.distance<0) {
			setTimeout(instance+".moveit()",this.time_increment);
		} else {
		if (this.direction > 0) this.lrstl.left = this.offset + 'px';
		if (this.direction < 0) this.lrstl.left = this.delta + this.offset + 'px';
		
		}
		if (this.positionx <= 0) this.lock = 0;
		
		
	}


}// LayerMover class


function init() {
	current_screen = 1;
	screen_size = (document.body.offsetWidth > 1024) ? document.body.offsetWidth : 1024;

	if (screen_size>395+485)
		polzunok_offset = screen_size-389-30;
	else
		polzunok_offset = 395+60;
	document.getElementById("background").style.width = (screen_size) + 'px';
	document.getElementById("Polzunok").style.left = parseInt(polzunok_offset) + 'px';
	// configure tape layer
	document.getElementById("tape").style.width = (screen_size + halfcamera)*6 + 'px';
	document.getElementById("tape").style.left  = -1*halfcamera + 'px';
	//MoveTape  = new LayerMover("MoveTape","tape",screen_size + halfcamera,0);
	MoveTape  = new LayerMover("MoveTape","tape");
	MovePolz = new LayerMover("MovePolz","Polzunok");
	document.getElementById("BackBut").style.visibility = "hidden";
	document.getElementById("GoBut").style.visibility = "visible";
	pngfix();
	document.getElementById("tape").style.visibility = "visible";
}

function moveRight() {
	if (MoveTape.lock == 1 || MovePolz.lock == 1) return;
        if (current_screen < 6) {
	        offset = -current_screen*(screen_size+halfcamera)-halfcamera;
	        //MoveTape.reset();
	        //MoveTape.moveit(screen_size + halfcamera,offset,1);
	        MoveTape.run(screen_size + halfcamera,offset);
		
	// Polzunok
	switch (current_screen) {
		case 1: MovePolz.run(-68,polzunok_offset); break;
		case 2: MovePolz.run(-83,polzunok_offset+68); break;
		case 3: MovePolz.run(-54,polzunok_offset+68+83); break;
		case 4: MovePolz.run(-61,polzunok_offset+68+83+54); break;
		case 5: MovePolz.run(-65,polzunok_offset+68+83+54+61); break;
	}
	current_screen++;
	if (current_screen == 6) document.getElementById("GoBut").style.visibility = "hidden";  
	document.getElementById("BackBut").style.visibility = "visible";
	} 
}

function moveLeft() {
	if (MoveTape.lock == 1 || MovePolz.lock == 1) return;
        if (current_screen > 1) {
	        offset = -(current_screen-1)*(screen_size+halfcamera)-halfcamera;
	        MoveTape.run(-1*(screen_size + halfcamera),offset);
	// Polzunok
	switch (current_screen) {
		case 2: MovePolz.run(68,polzunok_offset); break;
		case 3: MovePolz.run(83,polzunok_offset+68); break;
		case 4: MovePolz.run(54,polzunok_offset+68+83); break;
		case 5: MovePolz.run(61,polzunok_offset+68+83+54); break;
		case 6: MovePolz.run(65,polzunok_offset+68+83+54+61); break;
	}

		current_screen--;
	if (current_screen == 1) document.getElementById("BackBut").style.visibility = "hidden";
	document.getElementById("GoBut").style.visibility = "visible";

	} 

}

function movePolzunokTo(page) {
	if (page == current_screen) return;
	if (MovePolz.lock == 1 || MoveTape.lock == 1) return;
	// register differences

        switch(page) {
        	case 1: value_p = 0; break;
        	case 2: value_p = 68; break;
                case 3: value_p = 68+83; break;
        	case 4: value_p = 68+83+54; break;
                case 5: value_p = 68+83+54+61; break;
        	case 6: value_p = 68+83+54+61+65; break;
        } 


	if (page>current_screen) {
		offset_p = parseInt(MovePolz.lrstl.left);
		delta_p  = offset_p - polzunok_offset - value_p;
        }
        else {
		pos_p = parseInt(MovePolz.lrstl.left);
		offset_p = polzunok_offset+value_p;
		delta_p  = pos_p-offset_p;
        }
        MovePolz.run(delta_p,offset_p);

	// now tape
	
	//alert(offset_t )
	delta_t  = (screen_size + halfcamera)*(page-current_screen);
	if (page>current_screen) 
	offset_t = parseInt(MoveTape.lrstl.left)-(screen_size + halfcamera)*(page-current_screen); 
	else
	{
		offset_t = parseInt(MoveTape.lrstl.left);//+(screen_size + halfcamera)*(page-current_screen+1);
	}
	MoveTape.run(delta_t,offset_t);

	current_screen = page;
	if (current_screen == 6) document.getElementById("GoBut").style.visibility = "hidden"; else document.getElementById("GoBut").style.visibility = "visible";
	if (current_screen == 1) document.getElementById("BackBut").style.visibility = "hidden"; else document.getElementById("BackBut").style.visibility = "visible"
}

function pngfix() {

	var arVersion = navigator.appVersion.split("MSIE")
	var version = parseFloat(arVersion[1])

	if ((version >= 5.5) && (document.body.filters) && (version < 7)) 
	{
	   for(var i=0; i<document.images.length; i++)
	   {
	      var img = document.images[i]
	      var imgName = img.src.toUpperCase()
	      if (imgName.substring(imgName.length-3, imgName.length) == "PNG")
	      {
	         var imgID = (img.id) ? "id='" + img.id + "' " : ""
	         var imgClass = (img.className) ? "class='" + img.className + "' " : ""
	         var imgTitle = (img.title) ? "title='" + img.title + "' " : "title='" + img.alt + "' "
	         var imgStyle = "display:inline-block;" + img.style.cssText 
	         if (img.align == "left") imgStyle = "float:left;" + imgStyle
	         if (img.align == "right") imgStyle = "float:right;" + imgStyle
	         if (img.parentElement.href) imgStyle = "cursor:hand;" + imgStyle
	         var strNewHTML = "<span " + imgID + imgClass + imgTitle
	         + " style=\"" + "width:" + img.width + "px; height:" + img.height + "px;" + imgStyle + ";"
	         + "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader"
	         + "(src=\'" + img.src + "\', sizingMethod='scale');\"></span>" 
	         img.outerHTML = strNewHTML
	         i = i-1
	      }
	   }
	}

}