​x
 
<html>
<head>
<script type="text/javascript">
function clickButton()
  {
  document.getElementById('button1').click()
  }
function alertMsg()
  {
  alert("Button 1 was clicked!")
  }
</script>
</head>
<body onload="clickButton()">
​
<form>
<input type="button" id="button1" onclick="alertMsg()" value="Button 1" />
</form>
​
</body>
</html>
​