Question

I am learning how to use JQuery to help check data availability.

I have written a function in a Controller for checking data input, and the URL is like this:
http://www.mywebsite.com/controllers/action/avariable

But the returned data was blank.

<script language="javascript"> 
    $(document).ready(function(){  
        $(document).change(function(){ 
            var usr = $("#data\\[User\\]\\[name\\]").val();
            $.post{"http://www.mywebsite.com/controllers/action/",
                usr,
                function(msg){alert(msg);}
            }
        });
    });   
</script>

<div id="username">
    <input type=text name="data[User][name]" id="data[User][name]">
</div>             

Here is the code of the Action:

function action($data=null){
    $this->autoRender = false;
    $result2=$this->__avail($data);           
    if($result2==1)
        {return "OK";}
    else
        {return "NOT";}           
}

Answer 1

You really should get known with FireBug

Your JavaScript looks extra wrong 🙂

First of all, inline javascripts should be formatted like this:

<script type="text/javascript">

Than check out the jQuery.post() docs and overall javascript syntax…