function sidenav(highlight1,subnav1) {
	var strTemp = new String();
	if ( highlight1 != '' && highlight1 !="nav__about_us" ) {
		document.getElementById(highlight1).className = 'topicon1'; // 'topicon1';	
		if (arguments.length == 1) {
			document.getElementById(highlight1).className = 'highlight menuItemActive';
		}
	}
	if ( subnav1 != '' && subnav1 !="subnav__about_us") {
		document.getElementById(subnav1).className = 'subtopicson1'; // 'subtopicson1';
		if (arguments.length == 2) {
			document.getElementById(subnav1).className = 'highlight menuItemActive';
		}
  	}
	if (arguments.length >= 3) { 
		var subhead2 = arguments[2];
  	  	document.getElementById(subhead2).className = 'topicon2'; // 'topicon2';
		if (arguments.length == 3) {
			document.getElementById(subhead2).className = 'highlight menuItemActive'; 
			document.getElementById(subhead2).parentNode.className = "menuItemActive";
		}
		if (arguments.length >= 4){
			var subcat2 = arguments[3];
			document.getElementById(subcat2).className = 'subtopicson2'; // 'subtopicson2';
			if (arguments.length == 4) {
			document.getElementById(subcat2).className = 'highlight menuItemActive';
			document.getElementById(subcat2).parentNode.className = "menuItemActive";
			document.getElementById(subcat2).parentNode.parentNode.className = "menuItemActive";
			}
		}			
	}
}