Armor Hit Point adjustment

[bodrin]

I'm trying to develop an adjustment that shows the Hit point total of a selected armor.

I've managed to create this

Final Phase 10000

~ If we're not enabled, get out now
      doneif (field[pIsOn].value = 0)

~ Lets multiply our armor bonus by 10 which should give us our HP total
  field[abValue].value += round(field[arBonus].value * 10,0,-1) 

~ Now lets add to the Hit point total to our name 
  field[livename].text &= "Armor HP " & field[abValue].value

which compiles but I get this error when HL loads

Attempt to access field 'arBonus' that does not exist for thing 'pBodObHdHp'

Likewise same error if I substitute arBonus with tACArmor.
Any suggestions.