userData Cookies

hello,
i have a question about microsofts userdata (this are alternative cookies)

so you can load them:

Code:

---

function load(){
var inputfield = document.form.userdata;
inputfield.load("file");
inputfield.value = inputfield.getAttribute("file");
}

---

(--> http://msdn2.microsoft.com/en-us/library/ms531424.aspx)

i would like to load the value of my userdata cookie into a variable so that i can return this value with my load function (as a string).. can you help me? thx