jquery if statement to check if there is a value of an input otherwise auto populate upon clicking link
<p>I have a simple <code>jQuery</code> statement like so:</p>

<pre><code>$(document).ready(function() {
    $('#ltc_link').click(function() {
        $('#USERDEFINE1').val( 'LT' );
        $('#PHONENIGHT').val( '(111)111-1111' );
        $('#INTERNET').val( 'NONE' );
        $('#last_purchase').val( 'N/A' );
        $('#last_purchase_date').val( 'N/A' );
    });
});
</code></pre>

<p>It populates the input fields when the link <code>#ltc_link</code> is clicked.</p>

<p>If there is already text input into one or all of the fields than i don't want the click/link function to overwrite what the user entered. I know in javascript I can do something like so:</p>

<pre><code>if (!third.value) { third.value = '(111)111-1111'; }
if (!fourth.value) { fourth.value = 'NONE'; }
if (!fifth.value) { fifth.value = 'N/A'; }
if (!sixth.value) { sixth.value = 'N/A'; }
</code></pre>

<p>Need some  help with the <code>jQuery</code> syntax. Thanks in advance.</p>
