How to jump if the AF flag is 1?

I want to check if auxiliary carry flag is 1 then do something. I can't find any reference regarding only auxiliary carry flag.

mov al,00011010b
mov bl,10011010b  
add al,bl
;jump  if AF == 1

Solution

There are no conditional jumps based on AF. The easiest solution, as Peter Cordes said, is to load the flags onto the stack or into AH and branch on that:

add al, bl    ; some operation that sets AF
lahf          ; load flags into AH
test ah, 10h  ; check if AF is set
jnz afset     ; branch to afset if AF was set

Alternatively, if you are willing to trash AL, you can use aaa on value 00h to check if half carry occured.

add al, bl    ; some operation that sets AF
mov al, 0     ; clear AL for testing
aaa           ; set CF = AF, trash AX
jc afset     ; branch to afset if AF was set