301 redirect with Godaddy domain??

[apollion]

Hi everybody..

I encountered problems with my domain as websitegrader detected that http://mydomain and www.mydomain are two different sites from a SE´s view.

So I made a forwarding in my godaddy cp but no change..

For my understanding it has to be like this:

Whether I type http:// or www. it should always lead me to the www.-site, is that correct??

But I don´t know how to set this up with godaddy, their helpdesk says it´s already like I want it, but websitegrader says different..

Plz help!

[apollion]

Anybody??

I need heelpp..all my afforts are useless when I can´t get this solved..