var img_back = new Image();
	img_back.src = 'common/back.gif';
	
	var img_back_over = new Image();
	img_back_over.src = 'common/back_over.gif';
	
	var img_next = new Image();
	img_next.src = 'common/next.gif';
	
	var img_next_over = new Image();
	img_next_over.src = 'common/next_over.gif';
	
	function swap_image(this_image)
	{
		var x = document.getElementById(this_image);
		x.src = 'common/' + this_image + '_over.gif';
	}
	function restore_image(this_image)
	{
		var x = document.getElementById(this_image);
		x.src = 'common/' + this_image + '.gif';
		
	}
	var t = 0;
	var pos_t = 0;
	var intervalProcess;
	var scr_ht;
	
	
	function move_old(y)
	{
		var scroller = document.getElementById('nav_scroll');
		var debug = document.getElementById('debug');
		debug.innerHTML = t;
		t = t + y;
		b = b + y;
		scroller.style.clip="rect(" + t + "0px,0px," + b + "px,60px)"
	}
	
	function move(y)
	{
		intervalProcess = setInterval("change_clip(" + y + ")",1);
	}
	
	function change_clip(y)
	{
		//var scrl = document.getElementById('nav_scroll');
		//var debug = document.getElementById('debug');
		//debug.innerHTML = scr_ht;
		var scroller = document.getElementById('nav_scroll');
		//debug(t);
		if(pos_t > 0 & y == -2)
		{
			stop();
			pos_t = 0;
		}
		else if(pos_t < -750 & y == 2)
		{
			stop();
			pos_t = -750;
		}
		else if (y == -2)
		{
			pos_t = pos_t - y;
			scroller.style.top=pos_t + "px";
		}
		else
		{
			pos_t = pos_t - y;
			scroller.style.top=pos_t + "px";
		}
		debug(pos_t);
	}
	
	function set_clip(ya)
	{
		var scroller = document.getElementById('nav_scroll');
		scroller.style.top=ya + "px";
		pos_t = parseInt(ya);
		debug(ya);
	}
	
	function debug(a)
	{
		//var debug = document.getElementById('debug');
		//debug.innerHTML = a;
	}
	
	function stop()
	{
		clearInterval(intervalProcess);
	}