 <p>You can use javascript to submit the form. To make it easier, give the form an id, here's an example that uses jQuery:</p> <pre><code>&lt;form id="paypal-form" action="https://www.sandbox.paypal.com/webapps/adaptivepayment/flow/pay" target="PPDGFrame" name = "paypal_form"&gt; &lt;input id="type" type="hidden" name="expType" value="light"&gt; &lt;input id="paykey" type="hidden" name="paykey" value="RETURNED_PAYKEY_GOES_HERE"&gt; &lt;input type="submit" id="submitBtn" value="Pay with PayPal"&gt; &lt;/form&gt; &lt;script&gt; $('paypal-form').submit(); &lt;/script&gt; </code></pre>