function trim (str, charlist)
{
	// Strips whitespace from the beginning and end of a string  
	// 
	// version: 1004.2314
	// discuss at: http://phpjs.org/functions/trim    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
	// +   improved by: mdsjack (http://www.mdsjack.bo.it)
	// +   improved by: Alexander Ermolaev (http://snippets.dzone.com/user/AlexanderErmolaev)
	// +      input by: Erkekjetter
	// +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)    // +      input by: DxGx
	// +   improved by: Steven Levithan (http://blog.stevenlevithan.com)
	// +    tweaked by: Jack
	// +   bugfixed by: Onno Marsman
	// *     example 1: trim('    Kevin van Zonneveld    ');    // *     returns 1: 'Kevin van Zonneveld'
	// *     example 2: trim('Hello World', 'Hdle');
	// *     returns 2: 'o Wor'
	// *     example 3: trim(16, 1);
	// *     returns 3: 6
	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 : '';
}