prototypejs : holding functionality till ajax request result come

i am using new to prototype and using its ajax functionality but not abl开发者_运维知识库e to set the values to return type my code is

var captchaRequest = new Ajax.Request('http://www.example.com/captcha/validate.php', {
       parameters: "captcha_code="+captcha_code,
   onSuccess: function(result) {

    if(result.responseText == 'true') {
     return true;
    } else {
     return false;
    }
                 alert('in ajax response');

       }
});
alert('after ajax')

what i want to do is execute some functionality after ajax call is complete and but my second alert which is 'after ajax' is getting executed before 'in ajax response'. I want to use code result from ajax response. please help.

Thank you, pankaj

---

You do not need to set it to async. Just call your function from within the onsuccess block.

  var captchaRequest = new Ajax.Request('http://www.example.com/captcha/validate.php', {
               parameters: "captcha_code="+captcha_code,
           onSuccess: function(result) {

        if(result.responseText == 'true') {
         **callMyFunction()**
         return true;
        } else {
         return false;
        }
                     alert('in ajax response');

           }
    });
    alert('after ajax')