CREATE TABLE table_77903 ("Driver" TEXT, "Constructor" TEXT, "Laps" FLOAT, "Time/Retired" TEXT, "Grid" FLOAT)

What is the top grid that roger williamson lapped less than 7?
SELECT MAX("Grid") FROM table_77903 WHERE "Driver" = 'roger williamson' AND "Laps" < '7'
SELECT MAX("Grid") FROM "table_77903" WHERE "Driver" = 'roger williamson' AND "Laps" < '7'