Openlink error 247 with use of functions

[sjaakvanesdonk]

Hello,

i am using progress 9.1b and connect to it with openlink multi tier drivers (4.x version). The conenction works fine and i am able to use standard sql code. When i start using functions the problems begin. What i wan to do is check a datetime field with the system date of the database and see how much months are between. The moths between may be at maximum 2.

Selecting the month part of a datefield works correct e.a.
select month(fieldname) from tabelname.

Now when i try to select the sysdate the errors begin e.a.

select month(fieldname), sysdate from tabelname
it results in teh error message:
<eb1>** Column sysdate not found in table xprr. (965)
State:S1000,Native:965,Origin:[OpenLink][ODBC][Progress Server]</eb1>

when is use the function months_between like this:

select moths_between(datefield1, datefield2) from tablename
i get this error:
<eb1>** Unable to understand after -- &quot;DECLARE&quot;. (247)
State:S1000,Native:247,Origin:[OpenLink][ODBC][Progress Server]</eb1>

can anyone help me with this problem.