Code for close any document after fraction of seconds?

Question

Dear All,

 

Once again I need your help. I need to code a program like when I download an email which is an PDF or Word file, when I open it, it will pop-up a window that this document is opened for 25 seconds only. After 25 seconds that document should be closed.

 

Can any one suggest me the way to do it? Or any link regarding it.

 

 

Thanks