web开发常用js功能性小技巧

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>

</HEAD>

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只能输入数字

在<body>...</body>之间的表单．
<form method="POST" name=form action="" onSubmit="return check();">
<p align="center">
请输入电话号码：<input type="text" name="tell" size="20">
<input type="submit" value="提交" name="B1"></p>
</form>

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e mail 合法性检查
function check()
{
if(document.register.email.value.length!=0)
{
if (document.register.email.value.charAt(0)=="." ||
document.register.email.value.charAt(0)=="@"||
document.register.email.value.indexOf('@', 0) == -1 ||
document.register.email.value.indexOf('.', 0) == -1 ||
document.register.email.value.lastIndexOf("@") 　　
　 ==document.register.email.value.length-1 ||
document.register.email.value.lastIndexOf(".")
==document.register.email.value.length-1)
{
alert("Email的格式不正確！");
document.register.email.focus();
return false;
}
}
else
{
alert("Email的不能为空！");
document.register.email.focus();
return false;
}
return false;
}
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页面右键屏蔽
<body oncontextmenu="return false">

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自动清除输入框中的空格

再<head>...</head>间加入
<SCRIPT LANGUAGE="JavaScript">

</script>

如下代码加入<body>区

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右键菜单的淡入淡出效果
<HTML><HEAD><TITLE>右键菜单的淡入淡出效果</TITLE>
<META content="text/html; charset=gb2312" http-equiv=Content-Type>
<SCRIPT language=JavaScript>
<!-- // RightClickMenu
var intDelay=10; //设置菜单显示速度，越大越慢
var intInterval=5; //每次更改的透明度
function showmenuie5(){
var rightedge=document.body.clientWidth-event.clientX
var bottomedge=document.body.clientHeight-event.clientY
if (rightedge<ie5menu.offsetWidth)
ie5menu.style.left=document.body.scrollLeft+event.clientX-ie5menu.offsetWidth
else
ie5menu.style.left=document.body.scrollLeft+event.clientX
if (bottomedge<ie5menu.offsetHeight)
ie5menu.style.top=document.body.scrollTop+event.clientY-ie5menu.offsetHeight
else
ie5menu.style.top=document.body.scrollTop+event.clientY
ie5menu.style.visibility="visible"
//ie5menu.style.visibility=""
ie5menu.filters.alpha.opacity=0
GradientShow()
return false
}
function hidemenuie5(){
//ie5menu.style.visibility="hidden"
GradientClose()
}
function highlightie5(){
if (event.srcElement.className=="menuitems"){
event.srcElement.style.backgroundColor="highlight"
event.srcElement.style.color="white"
}
}
function lowlightie5(){
if (event.srcElement.className=="menuitems"){
event.srcElement.style.backgroundColor=""
event.srcElement.style.color="#000000"
}
}
function jumptoie5(){
if (event.srcElement.className=="menuitems"){
if (event.srcElement.url != ''){
if (event.srcElement.getAttribute("target")!=null)
window.open(event.srcElement.url,event.srcElement.getAttribute("target"))
else
window.location=event.srcElement.url
}
}
}

function GradientShow() //实现淡入的函数
{
ie5menu.filters.alpha.opacity+=intInterval
if (ie5menu.filters.alpha.opacity<100) setTimeout("GradientShow()",intDelay)
}

function GradientClose() //实现淡出的函数
{
ie5menu.filters.alpha.opacity-=intInterval
if (ie5menu.filters.alpha.opacity>0) {
setTimeout("GradientClose()",intDelay)
}
else {
ie5menu.style.visibility="hidden"
}
}

function ChangeBG() //改变菜单项的背景颜色，这里的两种颜色值可以改为你需要的
{
oEl=event.srcElement
if (oEl.style.background!="navy") {
oEl.style.background="navy"
}
else {
oEl.style.background="#cccccc"
}
}
// -->
</SCRIPT>

<DIV class=menuitems url="javascript:click_obj(0)">后退</DIV>
<DIV class=menuitems url="javascript:click_obj(1)">前进</DIV>
<DIV class=menuhr><hr style="width:100%"></DIV>
<DIV class=menuitems url="javascript:click_obj(2)">刷新</DIV>
<DIV class=menuitems url="javascript:click_obj(3)">加入收藏夹</DIV>
<DIV class=menuitems url="javascript:click_obj(4)">查看源文件</DIV>
<DIV class=menuhr><hr style="width:100%"></DIV>
<DIV class=menuitems url="javascript:click_obj(5)">属性</DIV>

</DIV>
<![endif]-->

<SCRIPT language=JavaScript>
<!--
function click_obj(id){
switch(id){
case 0:
history.back()
break
case 1:
history.forward()
break
case 2:
window.location.reload()
break
case 3:
window.external.AddFavorite(location.href, document.title)
break
case 4:
window.location = "view-source:" + window.location.href
break
case 5:
document.all.WebBrowser.ExecWB(10,1)
break
}
}

if (document.all&&window.print){
ie5menu.className="cMenu"
document.oncontextmenu=showmenuie5
document.body.onclick=hidemenuie5
}
//-->
</SCRIPT>
</RIGHTCLICK>
</BODY></HTML>

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ie用activex实现打印我没有检测过版本，ie6下正常
<head>...</head>加入：
<SCRIPT LANGUAGE=javascript>

</SCRIPT>

在<body>...</body>加入：
<OBJECT classid=CLSID:8856F961-340A-11D0-A96B-00C04FD705A2 height=0 id=WB width=0>
</OBJECT>
<INPUT type="button" value="Set" id=button1 name=button1 onclick="setPrint();">
<INPUT type="button" value="Preview" id=button2 name=button2 onclick="previewPrint();">

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超链接提交表单
<script LANGUAGE="JavaScript">
function checkvalue()
{
if(document.welcomeform.nickname.value=="")
{
alert("昵称不能为空！");
return(false);
}
if(document.welcomeform.password.value=="")
{
alert("密码不能为空！");
return(false);
}
document.welcomeform.submit();
return(true);
}
</script>

在<body>...</body>之间加入如下代码：
<form name="welcomeform" method="post" action="welcome.asp">
<a href="#" onclick="javascript:checkvalue();return false:">登录</a>
</form>
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不允许缓存页面
使用java提供的方法，在jsp或者servlet中都可以
<%
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
%>

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待......................

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