Originally posted by Dag Almkvist
Thanks, it helped. But what I really did was to click an opponent where the "play as .." was blank and clicking the blank area didn´t start the game. How do I do then

If it is blank that means your rating does not meet the limits specified by the person who set up the game and posted it.

If you do not like any of the games that you are eligible for or cannot find a suitable one, I would suggest that you create your own and wait for someone to accept it. Give it a try.

Or you can send a challenge to a specific member. However you could run into the rating limit problem there as well, as limits can also be specified on the "my settings/challenge settings" page. Take a look.

Some members are very particular about who they will play, so it is also helpful if you send them a private message first and see if they would be interested in playing a game or two with you. If you see someone you would be interested in playing, click their username and look at their profile page. You will be able to read their profile if provided, see statistics about their game history, etc.

On the left side of their profile page you will see a message link that will allow you to send them a private message. When you receive a message you will see a message notification in the upper right side of your own page, telling you that you have a message waiting.
(I have sent this post to you as a message to give an example of how it works.)

I hope this helps.