img=new Image();
img.src='./i/b2.gif';
function sbmenu(id){
	sbmnu=document.getElementById('submenu_'+id);
	sbmnuimg=document.getElementById('submenuimg_'+id);
	if(sbmnu.style.display=='block'){
		sbmnu.style.display='none';
		sbmnuimg.src='./i/b2.gif';
	} else {
		sbmnu.style.display='block';
		sbmnuimg.src='./i/b1.gif';
	}
}