function urlencode(str) {
	return escape(str).replace('+', '%2B').replace('%20', '+').replace('*', '%2A').replace('/', '%2F').replace('@', '%40').replace('&', '%26');
}
/*

urlEncodeCharacter : function(c)
{
	return '%' + c.charCodeAt(0).toString(16);
};

urlDecodeCharacter : function(str, c)
{
	return String.fromCharCode(parseInt(c, 16));
};

urlencode : function( s )
{
      return encodeURIComponent( s ).replace( /\%20/g, '+' ).replace( /[!'()*~]/g, urlEncodeCharacter );
};

urldecode : function( s )
{
      return decodeURIComponent(s.replace( /\+/g, '%20' )).replace( /\%([0-9a-f]{2})/g, urlDecodeCharacter);
};
*/

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 : '';
}

function permittedCharacters(str, charlist) {

	if (! charlist ) charlist = 'abcdefghijklmnopqurstuvwxyzABCDEFGHIJKLMNOPQURSTUVWXYZ1234567890/.-_';
	
	var returnString = '';
	var stringLength = str.length;
	
	for (var i =0; i <= stringLength; i++) {
		if (charlist.indexOf(str[i]) >= 0) returnString += str[i];
	}
	
	return returnString;

}