function showHelp(topic) {
	
	topics = new Array("gettingstarted","homescreen","mappingbasics","mapfunctions","keyboard");
	
	for (i=0; i<topics.length; i++ ) {
		document.getElementById("content-" + topics[i]).style.display = 'none';
		document.getElementById(topics[i]).className = '';
	}
	
	
	document.getElementById("content-" + topic).style.display = 'block';
	document.getElementById(topic).className = 'sel';
}