How to use Ext.net control in MVC 3?

[programmerist]

i want to use Ext.net control in aspnet mvc 3 but i can not do that. Can you help me?

<h2>List</h2>
<div>
        <% Ext.Net.TabPanel tb = new TabPanel() { ID="tb1", Height = 300 };
           tb.Items.Add(new Ext.Net.Panel() { ID = "1", Title = "Test" });
           this.Page.Controls.Add(tb);

        %>
    </div>

But no result return to me ERROR:

Collection was modified; enumeration operation may not execute. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: Collection was modified; enumeration operation may not execute.