PHP with DATE_ADD did not work
<p>Thanks to everybody who gave me some advice and answers. As I'm so new to this, I must appologize for some poor questions and technical terms. I decided to use DREAMWEAVER to finish this and still have some problems.
These are the changes that I made:</p>

<p>1.Change 'expiry_date' field to NULL because when I submit the form with 'NOT NULL' it didn't get through (<code>expiry_date</code> DATE NULL ,).</p>

<p>2.This is the code that I have</p>

<pre><code>if ((isset($_POST["MM_insert"])) &amp;&amp; ($_POST["MM_insert"] == "form1")) 
{
    $template = "INSERT INTO expirydate_table "
              . "(firstname, lastname, email, password, "
              . "signup_date, expiry_date) "
              . "VALUES (%s, %s, %s, %s, %s, %s)";

    $insertSQL = sprintf(
        $template,
        GetSQLValueString($_POST['firstname'], "text"),
        GetSQLValueString($_POST['lastname'], "text"),
        GetSQLValueString($_POST['email'], "text"),
        GetSQLValueString($_POST['password'], "text"),
        GetSQLValueString($_POST['signup_date'], "date"),
        GetSQLValueString($_POST['expiry_date'], "date")
    );
</code></pre>

<p>3.The form with the hidden fileds of 'signup_date' and 'expiry_date'</p>

<pre><code>&lt;input type="hidden" name="signup_date" value="&lt;?php echo $row_RecRegister3['NOW()']; ?&gt;"&gt;
&lt;input type="hidden" name="expiry_date" value="&lt;?php echo $row_RecRegister3['DATE_ADD(NOW() , INTERVAL 30 DAY))']; ?&gt;"&gt;
&lt;input type="hidden" name="MM_insert" value="form1"&gt;
</code></pre>

<p></p>

<p>Result:</p>

<ol>
<li>I can submit the form and <code>signup_date</code> displays in database.</li>
<li><code>expiry_date</code> did not show any data.</li>
</ol>

<p>Question:</p>

<ol>
<li>Is there any function to make it work or replace 'DATE_ADD(NOW(), INTERVAL 30 DAY)'?</li>
</ol>
