Add '0' to string if HH:MM.SS string is not formatted with double digit seconds

script.js

var str = '31:21.92';
var markS = str.match('[^.]*$'); // Find everything after '.'
if (markS.toString().length < 2) { // Check lenght of output
	console.log(markS);
	console.log(str + '0'); // When oput is less than 2 it needs an extra 0
} else {
	console.log(markS);
	console.log('It\'s OK');
}