Where's no problem using an event to call an ajax call for a data saving function (saveData), but timed, automatic data saving by calling this function at different interval failed without error.  See code below.  Know why?

Thanks in advance.

1. 
   
2.   /* auto data saving; */  
3. // try 60 seconds first
4. setTimeout("saveData()",60000);
5. 
   
6. 
   
7.   var saveData = function() {
8. // use jQuery to send form
9. $(document).ready(function() { 
10. $("#myform").submit(sendForm); 
11. return false;
12. });
13. 
    
14. console.log("after form submission by jquery");
15. // iterate every 5 minutes
16. // do 60 seconds for now
17. setTimeout("saveData()",60000);
18. 
    
19. }
20. 
    
21. function sendForm() { 
22. console.log('sendForm called');
23. $.post('mySavedata.cgi',$("#myform").serialize(),function(data,status){ 
24. $("#inform").html('Saved!') });
25. console.log('auto saved');
26. 
    
27. setTimeout(function(){document.getElementById('inform').innerHTML = ""},3000);
28.     return false 
29. }