I am working on a sheet and I need a particular cell to return text dependant on whether certain conditions are met, thus far I have written this formula:

=IF(O15<K15,"NO",IF(O15>J15,"NO",IF(O15<J15,"YES",IF(O15=J15,"YES",IF(O15,"","N/A")))))

The first 4 "IF's" return what they're suppose to however the last IF should return a "N/A" because the cell [referenced] is blank - but it doesn't it returns "NO"

can anyone help me please