CREATE TABLE table_50007 ("Tie no" FLOAT, "Home team" CLOB, "Score" CLOB, "Away team" CLOB, "Date" CLOB)

What was the tie number for the round against visiting opponent Newcastle United?
SELECT "Tie no" FROM table_50007 WHERE "Away team" = 'newcastle united'
SELECT "Tie no" FROM "table_50007" WHERE "Away team" = 'newcastle united'