jQuery adding 2 numbers from input fields
<p>I am trying to add two values of alert boxes but I keep getting a blank alert box.  I don't know why.</p>

<pre><code>$(document).ready(function(){
    var a = $("#a").val();
    var b = $("#b").val();   
    $("submit").on("click", function(){
        var sum = a + b;
        alert(sum);         
    })
})
</code></pre>
