PHP Submit based on entry

<form method="POST">
   if (isset($_GET['name'])){
      $searchname = $_GET['name'];

            <td><input type='Text' name='name' Value='<?=$searchname?>'></td>
            <td colspan='3'><input type='Submit' value='Search'></td>

Above I have a basic variable passed in from another page via URL. This variable is passed into a text box. When I get to the page that this is on, I want to have it search automatically, instead of me pressing the submit button. How does one do this?