master.dbo.dba_GetSQLForSpid

while running this script

 -- Do not lock anything, and do not get held up by any locks.
   SET TRANSACTION ISOLATION LEVEL READ
      UNCOMMITTED
 

   -- If there are blocked processes...
   IF EXISTS(SELECT 1 FROM sys.sysprocesses WHERE
      blocked != 0)
   BEGIN
 

      -- Identify the root-blocking spid(s)
      SELECT  distinct t1.spid  AS [Root blocking spids]
         , t1.[loginame] AS [Owner]
         , master.dbo.dba_GetSQLForSpid(t1.spid) AS
            'SQL Text'
         , t1.[cpu]
         , t1.[physical_io]
         , DatabaseName = DB_NAME(t1.[dbid])
         , t1.[program_name]
         , t1.[hostname]
         , t1.[status]
         , t1.[cmd]
         , t1.[blocked]
         , t1.[ecid]
      FROM  sys.sysprocesses t1, sys.sysprocesses t2
      WHERE t1.spid = t2.blocked
        AND t1.ecid = t2.ecid
        AND t1.blocked = 0
      ORDER BY t1.spid, t1.ecid
 

      -- Identify the spids being blocked.
      SELECT t2.spid AS 'Blocked spid'
         , t2.blocked AS 'Blocked By'
         , t2.[loginame] AS [Owner]
         , master.dbo.dba_GetSQLForSpid(t2.spid) AS
            'SQL Text'
         , t2.[cpu]
         , t2.[physical_io]
         , DatabaseName = DB_NAME(t2.[dbid])
         , t2.[program_name]
         , t2.[hostname]
         , t2.[status]
         , t2.[cmd]
         , t2.ecid
      FROM sys.sysprocesses t1, sys.sysprocesses t2
      WHERE t1.spid = t2.blocked
        AND t1.ecid = t2.ecid
      ORDER BY t2.blocked, t2.spid, t2.ecid
   END

i'm getting an error

Cannot find either column "master" or the user-defined function or aggregate "master.dbo.dba_GetSQLForSpid", or the name is ambiguous.

what's the problem here?