Hi, how do I enable jquery warnings?

Hi, how do I enable jquery warnings?

I'm sure this functionality must exist somewhere, but I can't find it. basically, I just spend over 3 hours until I realized that $("index") is not the proper spelling for selecting the index div. It would be swell if I could be alerted to such errors, I'm sure this is easily doable. I just need warnings whenever something fails, and this is a  clear case of failure, since so such property or function exists, right?

Thanks for your help