A jQuery script that checks the value of a cookie and creates a new cookie plus appends an additional value with "&" as a delimiter to the cookie value. Dependent on cookie.js plugin.

jQuery Cookie Reader Script

var value = $.cookie("myCookie"); //CHECK VALUE OF myCookie
var type = "my_value" // the additional cookie value
if (value == "" || value == null) { //if myCookie does not exist, create it and add type to value
    $.cookie("myCookie", type , { path: "/", domain: "mysite.com"}); //creates cookie called myCookie, sets value to type
} 
else if (value.indexOf(type) > -1) { //if value already exists in myCookie, do not duplicate
    return true;
} 
else {
    $.cookie("myCookie", value + "&" + type , { path: "/", domain: "mysite.com"}); //if myCookie does exist, add new value with delimiter
}