Fix sql query

routes/details.rb

@@ -45,7 +45,7 @@ class SignupSite < Sinatra::Base
       mysql = mysql_connect
       if session.key?(:invite)
         query            = mysql.prepare 'SELECT * FROM invites where `key` = ? LIMIT 1'
-        record           = query.execute(session[:username]).first
+        record           = query.execute(session[:invite]).first
         session[:parent] = Rack::Utils.escape_html(record['parent'])
       else
         insert = mysql.prepare 'INSERT INTO invites (`email`, `key`, `parent`) VALUES (?, ?, ?)'