display messages of a CALL TRANSACTION in an ALV

Hi,

i´ve got the following code:

CLEAR: i_messages, i_bdcdata.

REFRESH: i_messages, i_bdcdata.

• Execute transaction XXXX

LOOP AT i_lf1pro.

perform bdc_dynpro using '' ''.

......

call transaction 'XK02' using i_bdcdata

mode c_n

update c_s

messages into i_messages.

ENDLOOP.

Afterwards i want to display an identifying field of i_lf1pro with it´s corresponding message in an ALV.

The problem is that i´m not able to link this field to structure i_messages.

i´ve tried to replace i_messages with structure i_err where:

DATA: BEGIN OF i_err OCCURS 0,

DATA: newfield TYPE ...

INCLUDE STRUCTURE BDCMSGCOLL.

DATA: END OF i_mess.

LOOP AT i_lf1pro.

perform bdc_dynpro using '' ''.

......

MOVE i_lf1pro-newfield TO i_err-newfield.

call transaction 'XXXX' using i_bdcdata

mode c_n

update c_s

messages into i_err.

ENDLOOP.

but it doesn´t work.

How can i do it?

Best regards.