Own js tool Cookie encapsulation_javascript skills

/**
Cookie class
Put this class into the js file used to use
1.add(name,value,100); Add a cookie
2.get(name);
3.remove(name);
Use case:
Cookie.add("sk","ss",3);
alert(cookie.get("sk"));
Cookie.remove("sk");
*/
var Cookie=new function(){
/ /Add cookie
this.add=function(name,value,hours){
var life=new Date().getTime();
life =hours*1000*60;
var cookieStr =name "=" escape(value) ";expires=" new Date(life).toGMTString();
document.cookie=cookieStr;
};
//Get cookie value
this .get=function(name){
var cookies = document.cookie.split(";");
if(cookies.length>0){
var cookie=cookies[0].split( "=");
if(cookie[0]==name)
return unescape(cookie[1]);
}
return null;
};
// Delete cookies
this.remove=function(name){
var cookieStr=name "=" escape('null') ";expires=" new Date().toGMTString();
document.cookie =cookieStr;
};
}