help on step7

Dear All,
I am a lerner of plc please help me on below.

I have decleared start_add as temp word.
thanks in advance

OPN DB 5
L 100
L DBW 0
==I
JC LBL1
L DBW 0
L 1
+D
T DBW 0
T #start_add

L MB 111
SLW 9
SRW 12
T DBW[#start_add] // this statement giving error it says statement not permitted


LBL1: NOP 0

start_add needs to be a DWORD temp

I got it thanks