how do i call a stored procedure and retrieve the OUT paramters?

so far i've tried to add normal parameters and then retrieve them, but it doesn't seem to work.

eg
stored procedure is:
procedure doesSomething(foo OUT NUMBER)

from vb:
odatabase.Parameters.Add("foo", 0, OPARAM_OUTPUT, ORATYPE_NUMBER)
odatabase.ExecuteSQL("execute doesSomething(:foo);")

returnVal = odatabase.Parameters("foo").value;

in this case returnVal is set to "0" rather than any other number.

help!

thanks
mero