请问上用js怎么清除cookie

请教下用js如何清除cookie？
如，我想在网页上设置按钮“清除cookie”，当点击此按钮后，就清除名为了test的cookie所有值！

[解决办法]

JScript code

var Cookie=new Object(); Cookie.setCookie=function(name, value, option){     var str=name+'='+escape(value);     if(option){         if(option.expireHours){             var d=new Date();             d.setTime(d.getTime()+option.expireHours*3600*1000);             str+='; expires='+d.toGMTString();         }         if(option.path) str+='; path='+option.path;         if(option.domain) str+='; domain='+option.domain;         if(option.secure) str+='; true';     }     document.cookie=str; } Cookie.getCookie=function(name){     var arr = document.cookie.split('; ');     if(arr.length==0) return '';     for(var i=0; i <arr.length; i++){         tmp = arr[i].split('=');         if(tmp[0]==name) return unescape(tmp[1]);     }     return ''; } Cookie.delCookie=function(name){     this.setCookie(name,'',{expireHours:-1}); } /**How to use it Cookie.setCookie('own','this is cookie test!'); alert(Cookie.getCookie('own')); Cookie.delCookie('own'); alert(Cookie.getCookie('own')); **/