Auto Completion: How Do I Reset Settings

I'm not sure what I did but my autocompletion doesnt perform the way I want it to.  If I type in VAR, the autocompletion highlights VARY when I would have thought VAR would be the first option.  Everytime I try to type in FUNCTION, I get FUNCTIONKEYCODERE.  How do I change the autocompletion back to the default settings?  It is very frustrating to type like this.  

Thanks.