is there anything wrong with this formula?

this formula will be placed in F19/Age cell, my aim is to calculate the age of people based on their date of birth, i have modified whatever advice you people have graciously offered, i am grateful for the advice u have offered...

=IF(F19="",IF(G19="","",DATEDIF(G19,TODAY(),"y")), "")

F19 is the Age, G19 is the Date of Birth field

Just to interpret what I am trying to do, if F19/Age field is blank, then only I will check, if the G19/Date of birth cell is empty, then the F19 cell will be blank, whereas if there is a date, then it will calculate the age and display it in the Age field...

somehow, there is something wrong as no matter whatever the condition is, the cell outputs a value of '0'...