Help w/ Update Query

[SusanK4305]

Well seeing as I can't post this to the first part of the Question I just made another Question.

I have an Update SQL and need to take what I have and add to it.
What I wish to do:
1. IIf Max (tB.[Action Type]= 'Sent to EOD'& tB.[Action Date]not Null
THEN tA.[To EOD Date]= Null
But Max tB.[Action Type]='Sent to EOD',tB.[Action Date] must be after Max tB.[Action Type]='New Security Packet',tB.[Action Date]

This is what I have: UPDATE [tblDallas PSU Database] AS tA INNER JOIN [tblAction Log] AS tB ON tA.[Social Security Number]=tB.[Social Security Number] SET
tA.[Intake Delay Date] = IIf(tB.[Action Type]='Delayed',tB.[Action Date],tA.[Intake Delay Date]),
tA.[To EOD Date] = IIf(tB.[Action Type]='Sent to EOD',tB.[Action Date],tA.[To EOD Date]),
tA.[Received Date] = IIf(tB.[Action Type]='New Security Packet',tB.[Action Date],tA.[Received Date]),
tA.[e-QIP Invite Date] = IIf(tB.[Action Type]='E-Qip Initiation',tB.[Action Date],tA.[e-QIP Invite Date])
WHERE (tB.[Action Type] In ('Delayed','Sen t to EOD','New Security Packet','E-Qip Initiation'));