Javascript to automatically update current date on form when you open it every time?

Hi,

Wondering if I can get your expert help once again,

I have a form with the script below, however every time I open the date does not change to the current date which I need? Don't understand where I am going wrong with the script below?

// get current system date object

var oNow = new Date();

// set value to formatted date string

event.value = util.printd("dd/mmm/yyyy", oNow);

Many Thanks