var sShow  	= '';
	var sHide  	= 'none';

	function get_layer_obj(ID) {

		if (window.document.all) {
			if (eval("window.document.all."+ID))
				 return eval("window.document.all."+ID+".style");
			else return -1;
		}

		if (typeof(window.document.getElementById)=="function") {
			if (window.document.getElementById(ID))
				 return window.document.getElementById(ID).style;
			else return -1;
		}

		sShow = '';
		sHide = 'none';

		return -1;
	}

	function show_layer(ID) {
	 	get_layer_obj(ID).display = sShow;
	}

    function hide_layer(ID) {
     	get_layer_obj(ID).display = sHide;
    }

	function tl_help(ID) {
		if (ID==1) {
			hide_layer('no_help');
			show_layer('help');
		} else {
			hide_layer('help');
			show_layer('no_help');
		}
	}