title: Test if a file exists with javascript
body: <p>This question has already been asked <a href="https://stackoverflow.com/questions/3646914/how-do-i-check-if-file-exists-in-jquery-or-javascript">here</a> and <a href="https://stackoverflow.com/questions/5115141/check-if-a-file-exists-locally-using-javascript-only">here</a>. But I have tried three of the answers with no good luck. I am using a system called Niagara which is acting as a web server, which may be the reason these techniques did not work. Nonetheless, I feel there must be a way to check for the existence of a file, not the existence of a 404 or 200 or 0.</p>