assign negative sign

Hi all,

I have to attatch a negative sign againgt amount. like - 345.00

i am doing like this.

{ write ibsak-WRBTR to itab_main-amount.

concatenate '-' gamount into itab_main-amount .

condense itab_main-amount no-gaps . }

Debugger shows amount and also '-' sign but in printout only '-' sign is comming not amount.

Can u rectify me.