为什么不触发此警报框？ 在这里追鬼？

Question

I'm getting crazy already:

I have exactly this same code on my application:

http://jsfiddle.net/MZbLW/144/

EXACTLY THE SAME.

However, on my application the SECOND alert box NEVER shows.

Here's the copy paste:

<script>    

    if (typeof jQuery != 'undefined') {

    alert("jQuery library is loaded!");

}else{

    alert("jQuery library is not found!");

} // yes I'm this desperate! 

    $(document).ready(function() {

        // Using on method
        $(".trigger").on("click", function()
        {        

            // Using length instead of size. Using === instead of ==
            if($('#localized fieldset').length === 1)
            {
                window.alert("PLEASE SHOW "); //THIS DOESN'T APPEAR;
            }
            else
            {
                $('#localized fieldset:last-child').remove();
                // Toggle visibility.
                $(".trigger").toggle();
            }

            //return false; //prevent default anchor action;


        });
    });
</script>
    <style>
    .linkRemove {
    display:none;}
    </style>

<div id="localized">
    <fieldset>
            <label>hello</label>
            <input type="text" />
    </fieldset>
</div>


<a class="trigger" href="#"> Add Translation ▼</a>
<a class="trigger linkRemove" href="#"> Remove Translation</a>

I'm aware that without accessing the application code itself, it's not easy to debug, but, a simple "What could it be" may help me figuring this out.

Please advice.

Answer 1

Issue solved.

It was related with the fact that the Application was running a different Jquery version of that on Jsfiddle.

The method "on" was not suported, hence, the fact we were getting different outputs with the same code.