Query with match against another table field...

Hello all,

I have this situation:

Table A
id int
string varchar(255)

Table B
id int
name varchar(255)

I need to compare all the city names with the strings in Table A to find in which strings the name of the cities are:

I was trying to make something like:

SELECT * FROM strings, cities WHERE match(strings.string) against (cities.name);

but I get:
ERROR 1210 (HY000): Incorrect arguments to AGAINST

do you have any suggestion?

Thank you in advance