I'm trying to automate a few features on our billing invoices, and for the life of me, I cannot get my formula to work out right. I'm trying to get a cell to look at the date in a certain cell and based on how many days old it is, display one of four results (Current, 30+, 60+, & 90+). The formula I'm trying is below:

= IF (L16<=30),"Current",IF (L16<=60),"30+",,IF (L16<=90),"60+",IF(L16>90),"90+"

To my eye, this looks correct, but somethings wrong.