I have tried the code below to get a list of all tables in a legacy database that have no key index, and I have looked many places in BOL for different possibilities, but am unable to come up with the solution as of yet. Is the code below possible with some modification? If not, what might be a better method?

DECLARE @TableName VARCHAR(100)
DECLARE TableNameCursor Cursor FOR
SELECT [name]
FROM sysobjects
WHERE xtype = 'U'
OPEN TableNameCursor
FETCH NEXT FROM TableNameCursor
INTO @TableName
WHILE @@FETCH_STATUS = 0
BEGIN

If ((EXEC sp_primarykeys WMSDBPRI)) IS NULL
PRINT @TableName

FETCH NEXT FROM TableNameCursor
INTO @TableName
END

CLOSE TableNameCursor
DEALLOCATE TableNameCursor
GO