Using Switch and IsNull commands together - Crystal XI

I am using the Switch command with success untilllooking for the NULL.  See attachment.  The following 2 codes work but do not find  NULL and replace it with "Unknown".
switch ({C_BILLING.PatientType}like "E", "Emergency Room",
        {C_BILLING.PatientType}like "I", "Inpatient",
        {C_BILLING.PatientType}like "O", "Outpatient",
        {C_BILLING.PatientType}like ' ', "Unknown Account(s)")
iif (IsNULL ({C_BILLING.PatientType}),"Unknown",
switch ({C_BILLING.PatientType}like "E", "Emergency Roomx",
        {C_BILLING.PatientType}like "I", "Inpatient",
        {C_BILLING.PatientType}like "O", "Outpatient"))

For testing,
I used:   iif (IsNULL ({C_BILLING.PatientType}),"Unknown", "xx")
It worked to return the "unknown".

What is wrong that will not allow either one of the first two codes to work?
Thank you....

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I don't know why those don't work

I would do it as

If IsNull({C_BILLING.PatientType}) then
    Your Switch or if statements.


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rwarren99Author Commented:

I am running XI
Any reason why my code would not work?
Thanks Again...
rwarren99Author Commented:
Thank you for the assistance...
As I stated, I don't know of a reason it doesn't.  It seems like it should but that may just be the way an iif works.

rwarren99Author Commented:
Thank you again for your assistance....
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