Typically the host will send an email or Instant Messenger invitation that contains the access code and a link that can be clicked on to join the meeting.
If the invitation you received did not include a seven digit access code/meeting number or a link to join the meeting, you will need to contact the host of the meeting for the access number of the meeting. (GatherPlace Support cannot provide this information to you.)

There are several ways for the host to determine what the access code is for one of their meetings.
If the meeting IS in progress, see the Meeting in Progress section below.
If the meeting is NOT in progress, see the Meeting Not in Progress section below.

When the meeting is in progress the fastest way to see the meeting information which includes the access code is to click the blue Info button on the GP4 interface as shown below.
This will open the Call Information dialog which contains the Meeting/Meeting Title, Access Code and Teleconferencing Options that the meeting is configured to use.

The Info button circled on the GP4 interface.

The GP4 Call Information dialog.

The recommended way to get the meeting information to your guests, which includes the access code, is to invite them using the Invite Wizard.
Using the Invite Wizard, you have the option to send the invitation via email, Instant Messenger or instruct the guests verbally over a telephone.

Please see this article on inviting guests to a meeting using both the Invite Wizard or the GatherPlace website.

This short video also shows the invitation process using the Invite Wizard: http://www.gatherplace.com/gp/flash-play.jsp?handle=invite-guests&key=72152

Tip: You can also hover the mouse cursor over the meeting name in the My Meetings list to display the meeting information.
The Access Code will be the seven digit number displayed in the information.