Can somebody tell me what is wrong with this?

I am trying to created a view and have a need for conditional logic:

Here is what I presently have (not working):
-----------------------
IF (ISDATE(COMPLETIONDATE) = 1)
BEGIN
CASE
WHEN DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) > (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') THEN 'GREEN'
WHEN DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) < (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') AND DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) > 0 THEN 'YELLOW'
WHEN DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) < 0 THEN 'RED'
END AS THRESHOLDSTATUS
END
ELSE
IF (ISDATE(COMPLETIONDATE) = 0)
BEGIN
CASE
WHEN DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) > (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') THEN 'GREEN'
WHEN DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) < (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') AND DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) > 0 THEN 'YELLOW'
WHEN DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) < 0 THEN 'RED'
END AS THRESHOLDSTATUS
END
-----------------------

Can someone tell me what I am doing wrong?

Basically I am trying to test to see if "completiondate" is a date and if it is then perform a case operation using it, if it is not a date then I want to perform the case operation using "targetcompletiondate".

Thanks...select THRESHOLDSTATUS =
CASE
WHEN DATEDIFF(d, case when ISDATE(COMPLETIONDATE) = 1 then COMPLETIONDATE else TARGETCOMPLETIONDATE end, RESET.RESET_UNIT.MCD) > (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') THEN 'GREEN'
WHEN DATEDIFF(d, case when ISDATE(COMPLETIONDATE) = 1 then COMPLETIONDATE else TARGETCOMPLETIONDATE end, RESET.RESET_UNIT.MCD) < (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') AND DATEDIFF(d, case when ISDATE(COMPLETIONDATE) = 1 then COMPLETIONDATE else TARGETCOMPLETIONDATE end, RESET.RESET_UNIT.MCD) > 0 THEN 'YELLOW'
WHEN DATEDIFF(d, case when ISDATE(COMPLETIONDATE) = 1 then COMPLETIONDATE else TARGETCOMPLETIONDATE end, RESET.RESET_UNIT.MCD) < 0 THEN 'RED'
END
from ...|||First problem: You have a column called "CompletionDate" which may contain something that is NOT A DATE?!?! That's a design issue right there...

Second problem: You are putting this in a VIEW? Complex logic such as this is better off in a stored procedure. You didn't provide your entire CREATE VIEW statement, but depending upon what you are trying to do, your task may not be possible.

You may be able to use nested CASE statements:
CASE WHEN ISDATE(COMPLETIONDATE) = 1
CASE WHEN DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) > (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') THEN 'GREEN'
WHEN DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) < (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') AND DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) > 0 THEN 'YELLOW'
WHEN DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) < 0 THEN 'RED'
END
ELSE
CASE WHEN DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) > (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') THEN 'GREEN'
WHEN DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) < (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE') AND DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) > 0 THEN 'YELLOW'
WHEN DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) < 0 THEN 'RED'
END
END AS THRESHOLDSTATUS

...or a single CASE statement with more complex criteria:
CASE
WHEN ISDATE(COMPLETIONDATE) = 1 AND (DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) > (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE')) THEN 'GREEN'
WHEN ISDATE(COMPLETIONDATE) = 1 AND (DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) < (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE')) AND (DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) > 0) THEN 'YELLOW'
WHEN ISDATE(COMPLETIONDATE) = 1 AND (DATEDIFF(d, COMPLETIONDATE, RESET.RESET_UNIT.MCD) < 0 THEN 'RED'
WHEN ISDATE(COMPLETIONDATE) = 0 AND (DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) > (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE')) THEN 'GREEN'
WHEN ISDATE(COMPLETIONDATE) = 0 AND (DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) < (SELECT GREEN FROM RESET.THRESHOLDS WHERE TYPE = 'SCHEDULE')) AND (DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) > 0) THEN 'YELLOW'
WHEN ISDATE(COMPLETIONDATE) = 0 AND (DATEDIFF(d, TARGETCOMPLETIONDATE, RESET.RESET_UNIT.MCD) < 0 THEN 'RED'
END AS THRESHOLDSTATUS|||I thought that that's what I gave the poster...?|||Yeah, you sniped me by 10 minutes. So you get kudos for being first, but I get points for verbosity!