function page_index(){
	this.scroll	= function(index){
		if(window.loading_pscroll){return;}
		index--;
		var demo    = document.getElementById('demoimglist');
		var k       = 0;
		var h       = 311*index;
		var speed   = 50*index;
		demo.style.top='0px';
		function move(){
			if(k < h){
				k                      += speed;
				if(k>h){k=h;}
				demo.style.top          = '-' + k + 'px';
				setTimeout(move,10);
				window.loading_pscroll  = true;
			}else{
				window.loading_pscroll  = false;
				window.loading_top      = k;
			}
		}
		move();
	};
}
var _p_index=new page_index();