Two bindings are not working in knockout.js
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I am using knockout.js on 2 Model , but this is not working. 

    function AppViewModel1(Name) {
        this.firstName = ko.observable(Name.fn);
        this.lastName = ko.observable(Name.ln);
    }
    
    function AppViewModel2(Name) {
        this.first = ko.observable(Name.fn);
        this.last = ko.observable(Name.ln);
    }
    
     ko.applyBindings(new AppViewModel1({ fn : "yahoo", ln: ".in" }));
     ko.applyBindings(new AppViewModel2({ fn : "gmail", ln: ".com" }));

Can anybody please explain me, where i am wrong?