crystal report connection problem

Hi ,
I am trying to call crystal report 8.5 from visual basic 6.0. Database is oracle. I designed the report using crystal report designer . It works fine but when I call it from visual basic application it generates run time error " Cant open sql server"

I cant understand error.

code is

crctrl.reportfilename="c:\test.rpt"
crctrl.sqlquery="select * from mytable"
crctrl.action=1

Error occur only when I call sqlquery method. Because I want to retrieve dynamic records.

This code works fine If I use sqlserver 2000. But not with oracle.
Remember database connection is odbc connection.

Is there any one to help me out. Thanks

imran