recent threads on main page giving error

[wizardsolutions]

I'm using the following syndication code:

                               <script type="text/javascript">
                        <!--
                                    for (var i = 0; i < 16; i++)
                                 {
                                           var my_string = threads[i].title.substring(0,40) + "..";                                      
         document.writeln("<tr  style='font-size: 13;'><td>&nbsp;&nbsp;&nbsp;<a href=\"forum/showthread.php?t="+threads[i].threadid+"\">"+my_string+"</a></td><td>"+threads[i].poster+"</td></tr>");

                                    }
                        //-->
                        </script>

For some reason it give the error "threads[i] has no properties. What am I doing wrong?