I am getting this error while trying to set up a counter which calculates the total time taken to fill a particular form .Have tried the following things,

//script





var timeStart;

var timeStop;



$(document).load(function() {

    timeStart = new Date();

});



$('#form_3').on('submit', function() {

    timeStop = Math.round((timeStart.getTime() - new Date().getTime()) / 1000);

    console.debug('time taken from load till submit: ' + timeStop);

});

//script

now getting error uncaught TypeError:Cannot read property 'getTime' of undefined.