​x
 
<html>
<head>
<script type="text/javascript">
function setFocus()
  {
  document.getElementById('text1').focus()
  }
function loseFocus()
  {
  document.getElementById('text1').blur()
  }
</script>
</head>
<body>
​
<form>
<input type="text" id="text1" />
<br />
<input type="button" onclick="setFocus()" value="设置焦点" />
<input type="button" onclick="loseFocus()" value="失去焦点" />
</form>
​
</body>
</html>
​