<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=GB2312"/>
<title> 4.6 人性化表单 </title>
<!--脚本部分-->
<script type="text/javascript">
function $(str) {return(document.getElementById(str));}
function check_submit(){
if($("txt_user_name").value==""){alert("请填写username");return(false);}
if($("txt_user_pass").value==""){alert("请输入password");return(false);}
if($("txt_user_pass_confirm").value=="") {alert("请输入确认password");return(false);}
$("submit_button").disabled=true;
return(false);
}
function mover(){
event.srcElement.focus();
event.srcElement.select();
}
function mblur(){
if(event.srcElement.value=="") event.srcElement.value="[输入username]";
}
function mclick(){
if(event.srcElement.value=="[请输入username]") event.srcElement.value="";
}
</script>
</head>
<body style="overflow:auto;">
<form action="" onsubmit="return check_submit();">
username: <br>
<input id="txt_user_name" onmouseover="mover();
onclick="mclick();" onblur="mblur();" value="[请输入username]"><br>
password: <br>
<input id="txt_user_pass" type="password" onmouseover="mover();" value="默认password"><br>
确认password:<br>
<input id="txt_user_pass_conform" type="password" onmouseover="mover();" value="默认password"><br>
<input type="submit" calue="提交" id=submit_button">
</form>
</body>
</html>
