<SCRIPT>
function check(obj){
if(obj.value.length>=5){
document.getElementById('s1').innerHTML="only five";
}
}
</SCRIPT>
<BODY>
<TABLE>
USE:<input type="text" name="t1" id="t1" onpropertychange="check(this)">(5埵悢帤)
<span id="s1"><span>
</TABLE>
</BODY>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-31j">
<title>Insert title here</title>
<script language="javascript" type="text/javascript">
var messageBoxId = "messageBox";
function getMsgElement() {
var divMsg = document.getElementById(messageBoxId)
if(!divMsg) {
divMsg = document.createElement("div");
divMsg.id = messageBoxId;
}
return divMsg
}
function showMsg(msg) {
var divMsg = getMsgElement();
divMsg.style.backgroundColor = "yellow";
divMsg.innerHTML = msg;
document.body.appendChild(divMsg);
}
</script>
</head>
<body>
<input type="button" value="showMessage" onclick="showMsg('Message');" />
</body>
</html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-31j">
<title>Insert title here</title>
<script language="javascript">
var messageBoxId = "messageBox";function showMsg() {
var inputText = document.getElementById("inputText").value; if (inputText == "") {
document.getElementById("errInfo").innerText = "Please input";
}}
</script>
</head>
<body>
<span id="errInfo"></span>
<input type="text" id="inputText"/>
<input type="button" value="showMessage" onclick="showMsg();" />
</body>
</html>用SPAN实现的.