<form method="GET">

    What is your name: <input type="text" size="20" id="myname" onkeydown = "if (event.keyCode == 1)  document.getElementById('mybutton').click()"   />
3
  <input type="text" style="display: none;" />

  <button type="button" id="mybutton">Submit</button>

</form>

<div id="hellomessage"></div>

​