A dynamique Field in ireport?

[salwa]

Hello:
I am using iReport to edit the report . In my data base i have field how his content dependent of other field.  I need to  retrive the value of the second field in the first field.

For example :

My first field in data base is  like: " the code of facture is $F{filed2} "

when i generate the report , i should have a result like this  for exemple :

the code of facture is 1452 

Can you help my please

Thanks

[shgl]

I have a field like $F{aab004}, i want to change the font size  when length($F{aab004})>20.

that means when length($F{aab004})<=20 then use default size ,else use another size.

Can i use style in ireport to solve this problem?