I know this is a pretty elementary question but here goes.
Row 1 I have titles. Some times the titles span columns A-D, other times
they span A-K. I would like to have a conditional format that says "if there
is something in the cell, color the background yellow, else don't do
anything".
I have tried to do a conditional format that says $1$1 "" but that does
not seem to work (it colors all the cells in row 1). What am I doing wrong?

Thanks in advance for your help!