Javascript Date

Hi,
I have a text field which shows the current date based on the following javascript-

event.value = util.printd("mmmm d, yyyy", new Date());

I want to be able to do the following-

1. The date should auto-refresh when opened in Adobe Reader. Right now I have to delete the date and tab out for it to show the current date. Otherwise it keeps showing the previous date.

2. I want to make the field editable so that the user can enter his own date if needed.

3. I want to add the weekday to the date format- (Thursday, June 15, 2007)

4. I want to make the form compatible for MAC.

Thanks
Raj