function showPrev()
{
	var m=document.getElementById('mainPic');
	var current=m.name.substr(3)*1;
	var next=(current==1)?12:current-1;
	m.src="gallery2/bm"+next+".jpg";
	m.name="pic"+next;
	}
function showNext()
{
	var m=document.getElementById('mainPic');
	var current=m.name.substr(3)*1;
	var next=(current==12)?1:current+1;
	m.src="gallery2/bm"+next+".jpg";
	m.name="pic"+next;
	}