nownum=0;
function go_next_div() {
	var a=document.getElementsByTagName('Div');
	var count=0;
	for(var i=0;i<a.length;i++){
	var val=a[i].getAttribute('id').substring(0,9);
		if(val=='wrap_list'){
			count++;
		}
	}
	if (count>1) {
		if (nownum < count-1) {
			for (i=0;i<count ;i++ )	{
				document.getElementById('wrap_list'+i).style.display='none'; 
			}
				nownum++;
				document.getElementById('wrap_list'+nownum).style.display='block'; 
		}
		else {nownum=0;
			for (i=0;i<count ;i++ )	{
				document.getElementById('wrap_list'+i).style.display='none'; 
			}
			document.getElementById('wrap_list'+nownum).style.display='block'; 
		}
	}
}

function go_before_div() {
	var a=document.getElementsByTagName('Div');
	var count=0;
	for(var i=0;i<a.length;i++){
	var val=a[i].getAttribute('id').substring(0,9);
		if(val=='wrap_list'){
			count++;
		}
	}
	if (count>1) {
		if (nownum > 0) {
			for (i=0;i<count ;i++ )	{
				document.getElementById('wrap_list'+i).style.display='none'; 
			}
				nownum--;
				document.getElementById('wrap_list'+nownum).style.display='block'; 
		}
		else {nownum=count-1;
			for (i=0;i<count ;i++ )	{
				document.getElementById('wrap_list'+i).style.display='none'; 
			}
			document.getElementById('wrap_list'+nownum).style.display='block'; 
		}
	}
}