Would anyone have a code snippet for this

[Sammy]

I am trying to add on the Purchase Order screen a user field that will show me the 
 

1. The Actual Budget Amount for the account and subaccount that have been entered in the transaction detail line.  Accthist.Annbdgt table. Field  where Ledgerid = 'BUDGET'
2. The Actual Used Amount for the account \subaccount that have been entered in the transaction detail line.  Sum of all Accthist.ptdbal00 to Accthist.ptdbal12   where ledgerID = " ACTUAL'
3. A Calculated Amount that is basically the remainder of Actual - Budget for the account/subaccount line.  So basically Subtract line 2 from line 1 above.
    
   

Would anyone have a code snippet I could use for this.

 

Thanks

Sam