Javascript url containing random number [duplicate]

This question already has an answer here:

• Javascript: url containing random number 4 answers

A friend is linking my page from his site. As I need users to avoid caching when visiting my page, I want the url to have this form:

http://ift.tt/2cL8ZlG

Where 1934337463447875 is random number.

As my friend does not have installed php, how can I build the link with the random number using Javascript?

Also my friend asked me to give him just the url, with no further functions as his page is already loaded with them. Can it be done?

Thanks a lot