Android Question Query SOAP service

Hello
I am query a SOAP service and i think some variables are not posting.
The query is the following

job1.Initialize("Job1", Me)
job1.PostString("http://www.lexiconsoftware.gr/vies/webservice.asmx/findafm?afm=045019634&key=mykey", str)

the response is that the "Afm" parameter is missing which i think is not going or some characters are not going.
If you run the string
http://www.lexiconsoftware.gr/vies/webservice.asmx/findafm?afm=045019634&key=mykey
in a browser you will get that the key is invalid which is the correct answer.

What do i have wrong?
Is it the correct way to call SOAP web services?

Thank you