<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<style>
*{
margin:0px;
padding:0px;
}
#div1{
position:absolute;
width:200px;
background:#F00;
color:#FFF;
display:none;
}
</style>
<script>
//点击右键出现自定义菜单
document.oncontextmenu=function(ev){
var oEvent= ev||event;
var oUl=document.getElementById("div1");
oUl.style.display="block";
oUl.style.left=oEvent.clientX+‘px‘;
oUl.style.top=oEvent.clientY+‘px‘;
return false;
}
document.onclick=function(){
var oUl=document.getElementById("div1");
oUl.style.display="none";
}
</script>
</head>
<body>
<div id="div1">
<ul id="ul1">
<li>aaa</li>
<li>bbb</li>
<li>ccc</li>
</ul>
</div>
</body>
</html>
普通写法 return false
输入框只能输入数字
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<script>
window.onload=function(){
var oTxt=document.getElementById(‘tex1‘);
oTxt.onkeydown=function(ev){
var oEvent= ev||event;
//alert(oEvent.keyCode);
if(oEvent.keyCode!=8&&(oEvent.keyCode<49||(57<oEvent.keyCode&&oEvent.keyCode<96)||oEvent.keyCode>105)){
return false;
};
};
};
</script>
</head>
<body>
<input type="text" id="tex1">
</body>
</html>
原文：http://www.cnblogs.com/zwn-lucky7/p/6926218.html