function str_pad (input, pad_length, pad_string, pad_type) {
    // Returns input string padded on the left or right to specified length with pad_string  
    // 
    // version: 1008.1718
    // discuss at: http://phpjs.org/functions/str_pad    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // + namespaced by: Michael White (http://getsprink.com)
    // +      input by: Marco van Oort
    // +   bugfixed by: Brett Zamir (http://brett-zamir.me)
    // *     example 1: str_pad('Kevin van Zonneveld', 30, '-=', 'STR_PAD_LEFT');    // *     returns 1: '-=-=-=-=-=-Kevin van Zonneveld'
    // *     example 2: str_pad('Kevin van Zonneveld', 30, '-', 'STR_PAD_BOTH');
    // *     returns 2: '------Kevin van Zonneveld-----'
    var half = '', pad_to_go;
     var str_pad_repeater = function (s, len) {
        var collect = '', i;
 
        while (collect.length < len) {collect += s;}
        collect = collect.substr(0,len); 
        return collect;
    };
 
    input += '';    pad_string = pad_string !== undefined ? pad_string : ' ';
    
    if (pad_type != 'STR_PAD_LEFT' && pad_type != 'STR_PAD_RIGHT' && pad_type != 'STR_PAD_BOTH') { pad_type = 'STR_PAD_RIGHT'; }
    if ((pad_to_go = pad_length - input.length) > 0) {
        if (pad_type == 'STR_PAD_LEFT') { input = str_pad_repeater(pad_string, pad_to_go) + input; }        else if (pad_type == 'STR_PAD_RIGHT') { input = input + str_pad_repeater(pad_string, pad_to_go); }
        else if (pad_type == 'STR_PAD_BOTH') {
            half = str_pad_repeater(pad_string, Math.ceil(pad_to_go/2));
            input = half + input + half;
            input = input.substr(0, pad_length);        }
    }
 
    return input;
}