/*
 * common javascript function
 * from http://www.dustindiaz.com/top-ten-javascript/
 */

function addEvent(elm, evType, fn, useCapture) {
	if (elm.addEventListener) {
		elm.addEventListener(evType, fn, useCapture);
		return true;
	} else if (elm.attachEvent) {
		var r = elm.attachEvent('on' + evType, fn);
		return r;
	} else {
		elm['on' + evType] = fn;
	}
}

function removeEvent(elm, evType, fn, useCapture) {
	if (elm.removeEventListener) {
		elm.removeEventListener(evType, fn, useCapture);
	} else if (elm.detachEvent) {
		elm.detachEvent('on' + evType, fn);
	} else {
		elm['on' + evType] = null;
	}
}

function toggle(obj) {
	if (typeof(obj) == 'object') {
		var el = obj;
	}
	else {
		var el = $(obj);
	}

	if (el.style.display != 'none') {
		el.style.display = 'none';
	} else {
		el.style.display = '';
	}
}

function $(id)
{
    if (document.getElementById) {
        return document.getElementById(id);
    } else {
        return document.all[id];
    }
}