Connect to OpenVPN on a Raspberry PI

[WJH1]

Hello.

I'm a newbie on Linux, but want to see if I can switch completely from Windows to Linux.
For most things I can find an alternative. But now I have the following problem

Recently I've got my Raspberry PI setup as a OpenVPN server via a tutorial on readwrite.
With this tutorial I created (serveral) client.ovpn files.

On my Android devices I installed OpenVPN connect and imported the .ovpn file. I can connect to the Open VPN on the Raspberry and it works fine.

My laptop is a 64-bit machine with a dual-boot Windows 7 and Linux Mint 17.1 Rebecca.
In Windows I installed OpenVPN and imported the .ovpn file. This also works fine just like my Android devices.

Now I want to connect to my OpenVPN server with Linux Mint 17.1 Rebecca
I installed OpenVPN in Linux and I am able to import te .ovpn-file. The only thing is that it keeps asking for my username. With the above mentioned tutorial I did not have to create a username, just the .ovpn files (and several other files).

Is there anyone who knows how I can connect Linux to my OpenVPN server on my Raspberry or if I can find the username in the .ovpn file?

Thanks.

(Sorry for my English, it is not my native language)