Jquery doesn't like script filename..

Jquery doesn't like script filename..


Hello jquery people, I was recently playing around with jquery for my own independent project outside of work, and i found something interesting that was driving me crazy for a bit. 
 
I dont know if its the IDE iam using or maybe jquery itself, but i had a script file called include/lookup.js and the scripts i wrote there which seemed perfectly fine to me never would run... so after alot of tedious debugging, I tried just renaming the filename from lookup.js to lookup1.js without changing any of the code in there, and it worked perfectly fine when i reloaded the page!, and just to check if it was the filename i changed it back to lookup.js without changing any code again and it stopped working.
 
I dont know if this has somethign to deal with JQuery, my IDE (Iam using Netbeans launch a JSP website and testing it with glassfish) or something that I myself did not notice.  THe code works as long as i dont name it lookup.js so thats how Iama get around it, but iam curious to know why this would happen. Thank you for your time.