This is because there aren't any table or table alias with tblJobBudget
identifier.
Your tables are:
tblJobAdv
tblApplication
tblPersonalInfo
But not:
tblJobBudget
If you need columns from table tblJobBudget
you should include tblJobBudget
in tables with a join
clause:
from tblJobAdv
inner join tblApplication
ON tblJobAdv.advid = tblApplication.advid
inner join tblJobBudget <--here
ON ...
inner join tblPersonalInfo
ON ...