Perosnalization Multiple values concatenation error

Hi

I am trying to personzalize field's prompt text

and the value that i use in Value section is:

=SELECT

TO_CHAR(round(

XX_GET_ITEMS_MISC_QTY_PACKAGE.ITEM_QTY_ONHAND_FUNCTION

(:ORDER.SHIP_FROM,

:LINE.SUBINVENTORY,

:LINE.INVENTORY_ITEM_ID,

:LINE.ORDER_QUANTITY_UOM

)

-

XX_GET_ITEMS_MISC_QTY_PACKAGE.ITEM_QTY_RESERVED_FUNCTION

(:ORDER.SHIP_FROM,

:LINE.SUBINVENTORY,

:LINE.INVENTORY_ITEM_ID,

:LINE.ORDER_QUANTITY_UOM

)

,5))available_qty

FROM DUAL

it works fine but i want to concatenate it with 'carton' for example to be like the blue

=SELECT

TO_CHAR(round(

XX_GET_ITEMS_MISC_QTY_PACKAGE.ITEM_QTY_ONHAND_FUNCTION