Concatenating the data from a single field

Question

hello!
I wanted to concatenate all the data in a field
field is like this:
FIELD1
sample1
sample2
sample3
sample4
Output is like this:
sample1, sample2, sample3, sample4
how do i code this? thanks!

Answer 1

ITS NOT WORKING GUYS..
Let me revise my question again..
table: QMAT
FIELD1   FIELD2
sample1   JP1
sample2   JP3
sample3   JP1
sample4   JP2
sample5   JP3
When there is 2 or more same data in FIELD2 report should output like this:
Report:
JP1 sample1, sample3
JP2 sample4
JP3 sample2, sample5
something like this.. take note that i have to select using query FIELD2 and then concatenate if there is more than 1 record in FIELD1
both field(FIELD1, FIELD2) will be assign in a field also using SQ02 infoset
displaying the report is using field my code is something like this but it outputs iterated data..
TYPES: BEGIN OF type_qmat,
      ART TYPE qmat-art,
      END OF type_qmat.
DATA: it_qmat TYPE standard table of type_qmat,
      wa_qmat LIKE LINE OF it_qmat.
DATA: SEP VALUE ', '.
SELECT ART FROM QMAT INTO TABLE IT_QMAT.
LOOP AT IT_QMAT INTO WA_QMAT.
IF SY-TABIX EQ 1.
CONCATENATE IQC_INSP WA_QMAT-ART INTO IQC_INSP.
ELSE.
CONCATENATE IQC_INSP WA_QMAT-ART INTO IQC_INSP SEPARATED BY SEP.
ENDIF.
ENDLOOP.