Date and timestamp cell when data is entered

[Rportz]

=IF(H2:K2<>"",IF(L2<>"",L2,NOW()),"")

I need the "Updated" cell to automatically date & time stamp when data is entered in cells H2, I2, J2 or K2. I keep getting the above error. I'm not sure why the error is in cell M2, but I've tried several things and can't seem to get this right. Any help out there?

I checked the Enable iterative calculation hoping to avoid a circular issue as well (not sure if that has anything to do with the issue I'm having)

 

[Fluff]

How about

=IF(OR(H2:K2<>""),IF(L2<>"",L2,NOW()),"")