How to pass ajax variable value to controller in codeigniter

Question

Here i want to pass the 'q' value from ajax to controller function in codeigniter.

ajax code:   
function getdata(str) 
    {
        if (str == "") {
            document.getElementById("yer").innerHTML = "";
            return;
        } else { 
            if (window.XMLHttpRequest) {
                // code for IE7+, Firefox, Chrome, Opera, Safari
                xmlhttp = new XMLHttpRequest();
            } else {
                // code for IE6, IE5
                xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
            }
            xmlhttp.onreadystatechange = function() {
                if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                    document.getElementById("bus").innerHTML = xmlhttp.responseText;
                }
            }
            xmlhttp.open("GET","<?php echo site_url('money_c/taxcalculator1'); ?>?q="+str,true);
            xmlhttp.send();
               window.location="<?php echo site_url('money_c/taxcalculator'); ?>"

        }
    }
controller:

    function taxcalculator1()
            {
                $bt=$_GET['q'];
                echo $bt;
            }

Here i want to pass the 'q' value from ajax to controller function in codeigniter.

Answer 1

As soon as you have started the Ajax request sending with this:

 xmlhttp.send(); 

You leave the page with this:

 window.location="<?php echo site_url('money_c/taxcalculator'); ?>" 

… which aborts the Ajax request, removes the place you are trying to edit with innerHTML and destroys the JavaScript that would be trying to do that anyway.

---

If you want to use Ajax then:

• Put the data you want to show to the user the response from taxcalculator1
• Use onreadystatechange to show it to the user
• Don't leave the page before that happens (remove the window.location line).

If you want to load an entirely new page:

• Don't use Ajax
• Just submit a form to a URL
• Display the data you want the user to see (in the form of an HTML document) in the response to that request