How to append text with variable

This FM i m using for pop-up massage

CALL FUNCTION 'POPUP_CONTINUE_YES_NO'

EXPORTING

DEFAULTOPTION = 'Y'

TEXTLINE1 =

TEXTLINE2 = ' is Balance quantity' & quant & 'Do you want to continue '

TITEL = '-'

START_COLUMN = 1

START_ROW = 6

IMPORTING

ANSWER = result

i want to display this massage in popup -- ' is Balance quantity' & quant & 'Do you want to continue '

"quant" is variable which giving quntity

this line is giving error while activating , so tell me how i append text with variable

thanks