Close File 24 hours After Opening

Question

(Not having experience with pdf java script), I've been trying for 5 or 6 weeks to write a script - to be placed in Document Scripts (I'd prefer to say away from form fields) - that keeps a file open 24 hours after it's first launched––and then closes. (It's a 24 hour trial version).
I've tried different configurations. (This following script works but doesn't serve my goal: Reason is, in the script below, the "final date" is fixed. The final date  has to be calculated as 24 hours (1440 * 60 * 1000) after the initial launch date.):
var curDate = new Date();
var finalDate = new Date("8/08/2011");
if(finalDate.getTime() < curDate.getTime())
{this.closeDoc(true);}
I've tried using the following as the launch date but I can't make it work:
var f = this.getField("Today");
f.value = util.printd("mm/dd/yy", new Date());
The user is free to open and close the file during the 24 hours: So: I'm also concerned that the initial "curDate" remain stable. If it doesn't, I must change that part of the script as well and use a "Date the file was opened" as a variable. I've triend to use calcluations - but have not been able to succeed. At least, I figured out, there are 3 variables: the open-file-date, the 24 hours after open file date, and current date. In the end, I check to see if the 24-hours-after-open file is < than current date and if so, closeDoc. At least I learned that much.
Can anyone help me? I bet it's simpler than what I'm making it out to be, but I'm burnt to a crisp - I've spend all my time on this and have come to realize, it's  above my skill level and could use some help..... thank you in advance
Clint

Answer 1

You should be aware that even if you get the code right, this method can easily be disabled simply by the user disabling JavaScript, or using a non-Adobe PDF viewer.
The main difficulty seems to be that you are not recording and storing the initial opening date/time. You will have to store this date somewhere, either in the document or in a global variable. The problem with storing it in the document is the modified document would have to be saved by the user, which may not happen. So that leaves using a global variable.
Your code could first check for the existence of the global variable that you set up for this, and if it doesn't exists, create it, set its value to the current date/time, and set it to be persistent. You do this with the global.setPersistent method: http://livedocs.adobe.com/acrobat_sdk/9.1/Acrobat9_1_HTMLHelp/JS_API_AcroJS.88.778.html
Read up on the other information on the global object in the documentation.
You then just need to compare the current date to this stored date whenever the document is opened. If the difference exceeds 24 hours, oyu cna close the document using the doc.closeDoc method: http://livedocs.adobe.com/acrobat_sdk/9.1/Acrobat9_1_HTMLHelp/JS_API_AcroJS.88.448.html
Here's a little information on date arithmetic: http://livedocs.adobe.com/acrobat_sdk/9.1/Acrobat9_1_HTMLHelp/JS_Dev_AcrobatForms.76.35.ht ml
And you should be able to find more with a search.
Again, this can't be considered secure or robust, but it may be sufficient for your needs.