function closeAllDrops(){
	var drops = new Array(
		'dropnav_visitors',
		'dropnav_businesses',
		'dropnav_members',
		'dropnav_programs',
		'dropnav_about'
	);
	for( var i=0; i<drops.length; i++ ){
		dropdown = document.getElementById( drops[i] );
		dropdown.style.visibility = "hidden";
	}
}

function navOn(name){
	closeAllDrops();
	mouseover(name);
	if( name != "nav_home" ){
		var dropdown = document.getElementById( "drop" + name );
		dropdown.style.visibility = "visible";
	}
	
}

function navOff(name){
	closeAllDrops();
	mouseout(name);
}