CREATE TABLE table_25288 ("Constituency" TEXT, "Winner" TEXT, "Party" TEXT, "Margin" FLOAT, "Runner-up a" TEXT, "Party a" TEXT)

What is the margin when k. balathandayutham is the winner?
SELECT MAX("Margin") FROM table_25288 WHERE "Winner" = 'K. Balathandayutham'
SELECT MAX("Margin") FROM "table_25288" WHERE "Winner" = 'K. Balathandayutham'