Sets empty string columns to NULL in a SQL Server table

NullifyColumns.sql

SET NOCOUNT ON;

DECLARE	@TABLE VARCHAR(100),
		@SQL VARCHAR(MAX);

SET		@TABLE = '';

SELECT @SQL = COALESCE(@SQL, '')
			+ CAST(	'UPDATE ' + @TABLE + ' ' +
					'SET [' + C.COLUMN_NAME + '] = NULL ' +
					'WHERE [' + C.COLUMN_NAME + '] = ''''; ' + Char(13)
			AS VARCHAR(MAX))

FROM	INFORMATION_SCHEMA.COLUMNS C
JOIN	sysobjects B
	ON	C.TABLE_NAME = B.NAME

WHERE	C.TABLE_NAME = @TABLE
AND		C.DATA_TYPE IN ('varchar','nvarchar')
AND		C.IS_NULLABLE = 'YES'
AND		B.xtype = 'U';

EXEC(@SQL);