var signup_roommate='';

function signup_toggle_shareroom() {
	var singsup=document.getElementById('singsup');
	var roommate=document.getElementById('roommate');
	var roommate_name=document.getElementById('roommate_name');
	if ( signup_roommate == '' && roommate_name != '' ) 
	{
	   signup_roommate=roommate_name.value; 
        }

	if ( singsup.checked ) { roommate.style.display='none';roommate.value = ''; }
	else { roommate.style.display = '';roommate.value=signup_roommate; }
}