using System;

using CMS.Forums;

using CMS.CMSHelper;

...

        // Get forum object

        ForumInfo fi = ForumInfoProvider.GetForumInfo("CustomForum", CMSContext.CurrentSiteID);

        // If forum exists

        if (fi != null)

        {

            // Create new thread object

            ForumPostInfo fpi = new ForumPostInfo();

            // Set properties

            fpi.PostUserID = CMSContext.CurrentUser.UserID;

            fpi.PostUserMail = CMSContext.CurrentUser.Email;

            fpi.PostUserName = CMSContext.CurrentUser.UserName;

            fpi.PostForumID = fi.ForumID;

            fpi.PostTime = DateTime.Now;

            fpi.PostApproved = true;

            fpi.PostText = "This is a forum post";

            fpi.PostSubject = "Post subject";

            // Save thread to database

            ForumPostInfoProvider.SetForumPostInfo(fpi);

        }