IF statement with a DATEDIF calculation in it

[Nev Bentley]

Is it possible to add a piece of text to say that there is no end date in the DateDif calculation I have this =IF(DATEDIF(J18,K18,"m"),"No End date") and I get the #VALUE returned

 

[rjmdc]

the formula i was using returned years.month
how do i add an if to this that if years.month <18 then "needs approval" otherwise "ok"

 

[rjmdc]

i tried this and am getting my results
=IF(DATEDIF([@DOB],TODAY(),"Y")<18,"Needs Approval","ok")
how can i correct that blank date of birth also generates needs approval or is missing instead of ok

also if i have this formula in a cell
can i override it manually with approval received or will it keep reverting to approval needed

 

[rjmdc]

whats wrong with this?
=IF(AND(DATEDIF([@DOB],TODAY(),"Y")<18,[@service]="otps internet",[@service]="otps phone",[@service]="otps clothing",[@service]="otps utilities"),"needs approval","ok")