Cascading Textbox in mvc4?

Hi I have two fields in my view CustomerName and ContactPerson. Before i kept these two field as dropdown field. Now I change the customer name field as autoComplete textbox and contact person field as dropdown field.

Before i kept these two field as Cascading dropdown fields.That is if i select theCusomerName the CustomerName related ContactPerson will automatically in ContactPerson dropdown.

Now I change that customer name field to textbox and contact person field as dropdown. Now what i want is if i type and select the CustomerName in customername textox, the CustomerName related ContactPerson have to load automatically in contactperson dropdown.

My Model

Visitors View Model

public Nullable CustomerID { get; set; }

public string CustomerName { get; set; }

public Nullable CustomerContactID { get; set; }

public string ContactPerson { get; set; }

My View

@Html.LabelFor(model => Model.CustomerName, new { @class = "control-label" })

@Html.TextBoxFor(model => Model.CustomerName, new { @class = "form-control" })

@Html.HiddenFor(model => Model.CustomerID)

@Html.Label("Contact Person", new { @class = "control-label" })

@Html.DropDownListFor(model => model.CustomerContactID, new SelectList(string.Empty, "Value", "Text"), "Please select a ContactPerson", new { @class = "form-control", type = "text", id = "CustomerContactID" })

My Jquery Code