定義和用法
focus() 方法用於在密碼域上設置焦點。
語法
passwordObject.focus()
實例
下面的例子可設置或移開密碼域上的焦點：
<html>
<head>
<script type="text/javascript">
function setFocus()
{
document.getElementById('password1').focus()
}
function loseFocus()
{
document.getElementById('password1').blur()
}
</script>
</head>
<body>
<form>
<input type="password" id="password1" value="thgrt456" />
<input type="button" οnclick="setFocus()" value="Set focus" />
<input type="button" οnclick="loseFocus()" value="Lose focus" />
</form>
</body>
</html>
實例2：<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>Untitled Document</title>
<script type="text/javascript">
function chg(){
document.getElementById("setfocus").value="";
}
function newChg(){
document.getElementById("setfocus").value="請輸入關鍵字";
}
</script>
</head>
<body>
<input type="text" name="name" size="15" class="input" id="setfocus" value="請輸入關鍵字" οnfοcus="chg()" οnblur="newChg()">
</body>
</html>
實例3
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>Untitled Document</title>
<script type="text/javascript">
function $(ID) {return document.getElementById(ID);}
function chg(){
$("setfocus").value="";
}
function newChg(){
if($("setfocus").value==""){
$("setfocus").value="請輸入關鍵字";
}
else{return $("setfocus").value }
}
</script>
</head>
<body>
<input type="text" name="name" size="15" class="input" id="setfocus" value="請輸入關鍵字" οnfοcus="chg()" οnblur="newChg()">
</body>
</html>