// Cross-browser implementation of element.addEventListener()
function addListener(element, type, expression, bubbling){
	bubbling = bubbling || false;
	if(window.addEventListener)	{ // Standard
		element.addEventListener(type, expression, bubbling);
		return true;
	} else if(window.attachEvent) { // IE
		return element.attachEvent('on' + type, expression);
	} else return false;
}

//Dynamically includes any script via Javascript
function include_dom(script_filename) {
	var html_doc = document.getElementsByTagName('head').item(0);
	var js = document.createElement('script');
	js.setAttribute('language', 'javascript');
	js.setAttribute('type', 'text/javascript');
	js.setAttribute('src', script_filename);
	html_doc.appendChild(js); //Attach the newly element to HTML->Head beginning
	return false;
}

// Powered by PHP.JS ( http://phpjs.org/ )
function trim(str, charlist) {
    var whitespace, l = 0, i = 0;
    str += '';
    
    if (!charlist) { // default list
        whitespace = " \n\r\t\f\x0b\xa0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000";
    } else { // preg_quote custom list
        charlist += '';
        whitespace = charlist.replace(/([\[\]\(\)\.\?\/\*\{\}\+\$\^\:])/g, '\$1');
    }
    
    l = str.length;
    for (i = 0; i < l; i++) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(i);
            break;
        }
    }
    
    l = str.length;
    for (i = l - 1; i >= 0; i--) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(0, i + 1);
            break;
        }
    }
    
    return whitespace.indexOf(str.charAt(0)) === -1 ? str : '';
}