Why does a Stored Procedure fail to execute reporting errors even though the SQL statement executed when run stand alone

I have  a stored procedure in my postgresql database

The procedure compiles without  any error  (see  screen)


When i tried to excute I got an error of a field lastnumber as not existing even though it exists in the table (see error screen)



I then  tried to replicate the stored procedure as just an ordinary sql statement and it executed properly  giving the desired result (see  screen)


Why am i having the error that a field existing in the database is being reported as not existing

I also attach the table with it Fields and Data  (see attached screen)


I will be grateful  for any advise on how to resolve this issue.

Olukay