CREATE TABLE table_45239 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Ground" TEXT, "Date" TEXT, "Crowd" FLOAT)

Name the Away team score which has an Away team of st kilda, and a Crowd of 8157?
SELECT "Away team score" FROM table_45239 WHERE "Away team" = 'st kilda' AND "Crowd" = '8157'
SELECT "Away team score" FROM "table_45239" WHERE "Away team" = 'st kilda' AND "Crowd" = '8157'