trying this
select tblPersonalInfo.companyname, tblJobBudget.title,tblJobBudget.lastmodifiedby,
tblJobAdv.advtitle, tblJobAdv.userId,
tblApplication.
This is because there aren't any table or table alias with tblJobBudget identifier.
Your tables are:
tblJobAdv tblApplicationtblPersonalInfoBut not:
tblJobBudgetIf 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 ...