jquery .hover() for navigation
<p>i make navigation function that changes navigation default image to hover image.</p>

<p>default image name is "main.png" and hover image is "main_hover.png"</p>

<p>i know how to extract image name from html src attribute by help of jquery, but i down know how to add additional string between file name "main" and file extension ".png"</p>

<p>my code so far:</p>

<pre><code>$(document).ready(function(){
    $(".nav").hover(function(){
        var default_button = this.src;
        // here is part where i need help with adding "_hover" to default_image
        $(this).attr('src', default_button) // i know i need this after image is not hovered
    });
});
</code></pre>
