To enter a challenge, find the player who is making the challenge and then using the drop-down selection list, select the player that is being challenged:

In the above example, Tim Stainton has logged in and the rule has been set that players can challenge a player up to 3 points above.

The star in the Status column indicates that a player is "under challenge" and cannot make another challenge of their own or be challenged until the challenge match has been played. So a challenge can be made to Chris Boyer or Colin Woods.

Having selected the player to challenge, click the Challenge button and an email will be sent to the player with details.

Selecting Outstanding Results from the Ladder list will show all matches with their status:

You can Enter Results here, cancel the challenge and also see the Status of any match.