function padString (str, width, paddingStr) {
paddingStr = paddingStr || '0';
str = str + '';
while (str.length < width) { str = paddingStr + str; }
return str;
}function pad (n, width, z) {
z = z || '0';
n = n + '';
while (n.length < width) { n = z + n; }
return n;
}