function collapsemenus(){
	m1=document.getElementById('mn1');
	m2=document.getElementById('mn2');
	m3=document.getElementById('mn3');
	m1.style.visibility='hidden';
	m1.style.display='none';
	m2.style.visibility='hidden';
	m2.style.display='none';
	m3.style.visibility='hidden';
	m3.style.display='none';
}
function showmenu(mnid){
	collapsemenus();
	document.getElementById(mnid).style.visibility='visible';
	document.getElementById(mnid).style.display='block';
}