using CMS.CMSHelper;

using CMS.SiteProvider;

using CMS.WorkflowEngine;

...

       // Get current site name (you can use code name of the required site instead)

       string siteName = CMSContext.CurrentSiteName;

       // Check if the site name is available

       if (siteName != null)

       {

           try

           {

               // Stop the site because we will change the domain of the site

               SiteInfoProvider.StopSite(siteName);

               // Get site info

               SiteInfo si = SiteInfoProvider.GetSiteInfo(siteName);

               if (si != null)

               {

                   si.DisplayName = "New dsiplay name";

                   si.Description = "New description";

                   // Change domain of the site

                   si.DomainName = "mynewdomain.com";

                   // Set new domain alias with default content language set to en-US

                   SiteInfoProvider.AddDomainAlias(siteName, "newdomainalias", "en-US");

                   // Save the changes

                   SiteInfoProvider.SetSiteInfo(si);

               }

               // Run the site

               SiteInfoProvider.RunSite(siteName);

               lblInfo.Text = string.Format("Site '{0}' has been edited.", siteName);

           }

           catch (RunningSiteException ex)

           {

               lblError.Text = "Site cannot be started.<br />Original exception: " + ex.Message;

           }

           catch (Exception ex)

           {

               lblError.Text = "Error when modifying site properties.<br />Original exception: " + ex.Message;

           }

       }