function ViewModel() {
         this.ListaArticoli= ko.observableArray([]),
         this.productLines= ko.observableArray([
                                         { text: "nome linea", value: "L1" },
                                         ,,,...         ]),      
         this.selectedLine= ko.observable(),
         this.load= ko.computed(function () {
             var selectedLine = this.selectedLine();
             if (!selectedLine) return;

             Load(0, 9, selectedLine.value);

         }, this),
         this.pendingRequest= ko.observable(false),
         this.EndOfData= ko.observable(false)
     };

var viewModel = new ViewModel();

function Load(Skip, Take, Line) {
    //if (!viewModel.pendingRequest()) {
    //    viewModel.pendingRequest(true);
           
        $.ajax({...

    //}
}