Search is not giving proper result

[development]

Dear all,

I am very new to mysql full-text search.
I am evaluating this feature for implementation of a search engine for our documents in database. We are using 'longtext' datatype for storing documents in table, with fulltext index.

I've created a temp table for testing

CREATE TBL_XX_TEST
(
FLD_ID INT,
FLD_DESC LONGTEXT,
FULLTEXT(FLD_DESC)
)

and the data is

FLD_ID | FLD_DESC
1 | This is AAA from XXX
2 | This is BBB from YYY
3 | This is CCC from ZZZ

now i m executing the query

SELECT * FROM TBL_RUSHIK_TEST
WHERE MATCH (FLD_DESC) AGAINST ('AAA'); -> gives me the 1st row

SELECT * FROM TBL_RUSHIK_TEST
WHERE MATCH (FLD_DESC) AGAINST ('This'); -> no result

Actually it should give me all the three rows. I m not able to identify what is the problem.

Please suggest me any solution for this.

Thanks
Rushik.