function setcookie(name,value){  
    var days = 30;  
    var exp  = new Date();  
    exp.setTime(exp.getTime() + days*60*60*24*1000);  
    document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString() + ";path=/";  
}  
  
function getcookie(name){  
    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));   
    if(arr != null){  
        return unescape(arr[2]);  
    }else{  
        return "";  
    }  
}  
  
function delcookie(name){
    var exp = new Date();   
    exp.setTime(exp.getTime() - 1);  
    var cval = getcookie(name);  
    if(cval != null){
        document.cookie= name + "=" + cval + ";expires=" + exp.toGMTString();
    }
}