var keymove=0;
function movepage()
{
	var dt=40;
	var dy=12;
	var c1=document.getElementById('page_wrap');
	var c2=document.getElementById('page_in');
	var top=parseInt(c2.style.marginTop);
	if(isNaN(top))top=0;
	var dh=c1.offsetHeight-c2.offsetHeight-120;
	top=top+dy*keymove;
	if(top<dh)
	{
		top=dh;
		keymove=0;
	} 
	if(top>0)
	{
		top=0;
		keymove=0;
	} 
	c2.style.marginTop=top+'px';
	if(keymove==0)return;
	setTimeout('movepage()',dt);
}
function movepageup()
{
	keymove=1;
	movepage();
}
function movepagedown()
{
	keymove=-1;
	movepage();
}
function movepagestop()
{
	keymove=0
}