quick test for file

[foobar.13]

Hello,

I am trying to devise a simple way to check to see if a file is on a
remote server, and if so, load that file. The need for this is because
I am running a few websites, and have a central server hosting all my
..js files. If this central server for some reason gets knocked offline
or looses internet, all of my other sites slow down while trying to
load the .js files that were held on the central server. What I am
wanting to do, is test to see if that server is up, if it is load up
the .js file, else just skip the file all together and try to keep page
loadtime to be short as possible. Is there any quick and simple way of
doing this?

Thanks...
Mr. Young