Can I cause a form to submit upon page load event?

I have a web site for a non-profit with a number of pages, and I set it up using a master page.  There is a 'Donate' button on the 'default.aspx' page and I have the menu set up to open another page called 'donate.aspx'.  On 'donate.aspx' I've included code we received from PayPal shown here;
<form action="https://www.paypal.com/cgi-bin/webscr" method="post"> <div> <input type="hidden" name="cmd" value="_s-xclick" /> <input type="hidden" name="hosted_button_id" value="NOTTHEREALVALUE" /> <input type="image" src="https://www.paypalobjects.com/en_US/i/btn/btn_donateCC_LG.gif" name="submit" alt="PayPal - The safer, easier way to pay ...