how can i tell the difference

[jockmcd]

i caught a fish tonight and i dont know whether its cod , haddock or pollack , i reckon its pollack but so confusing all over the net , do you guys know any visual differences between them that i could distinguish

p.s i took a photo on my phone so i could post it on here from my computer , how do i post pics on my post ?

p.s.s also got 2 dogfish , put them back in are they any good for eating , anyone know , ta

Jock