The problem is you can't pass MyUser as parameter from JQuery because JQuery doesn't know the class MembershipUser. Remember that JQuery is a client side language and MembershipUser is defined in C# on the server side.
You could pass the properties that you need from the MyUser object to the Process action using GET as follows (supossing that the MyUser object has and ID an a Name):
$('#Link').click(function () {
$.ajax({
url: http://localhost/Account/Process,
type: 'GET',
data: {
id: "@ViewBag.MyUser.ID",
name: "@ViewBag.MyUser.Name"
},
success: function () {
},
error: function () {
}
});
The action should be something like this:
public ActionResult Process(int id, string name)
{
//Do something
}
I hope it helps you!