function change_visibility(name, only_visible)
{
	if(only_visible=="false"){
		if(document.getElementById(name).style.display == 'block'){
			document.getElementById(name).style.display= 'none';
		}
		else
			document.getElementById(name).style.display = 'block';
	}
	else
		document.getElementById(name).style.display = 'block';
}