Calculating the enddate

[BasSchouten]

I'v got two tables SAL and DVB
DVB contains info on a workingcontract
SAL contains information historic salaries on those workingcontracts. The tables consists of the following columns:

DVB:
DVBDVBIDN    (identity)
DVBDVBDTB    (startdate of contract)
DVBDVBDTE    (enddate of contract, 9999-12-31 if no enddate)

SAL:
SALSALIDN    (identity)
SALDVBIDN    (foreign key into DVB)
SALSALSAL    (salary)
SALSALDTB    (Startdate of this salary)

I want to create a view of salaries of a certain contract and include the enddate of that salary. The enddate of salary X should be calculated as follows:
If there exists a salary Y of the same contract that starts after salary X, then the enddate of salary X is the startdate of Salary Y - 1 day.
If salary X is the latest salary, then the enddate of the salary is the enddate of the contract.

I'v created the separate coding for the two options:
Option 1:

SELECT MIN(SALSALDTB)-1 FROM PDPSAL01 SAL2
WHERE SAL1.SALDVBIDN = SAL2.SALDVBIDN
  AND SAL2.SALDVBDTB > SAL1.SALSALDTB

Option 2:

SELECT DVBDVBDTE FROM PDPDVB01
WHERE SAL1.SALDVBIDN = DVBDVBIDN

How do i incorporate these two options as one field in a view definition? Bas Schouten
System Development & Webdesign
CBIS BV Holland