Updating a textbox in a Repeater

Question

I created a repeater to display my data inside a dataTable of Session("Cart") however i have a problem. I do not know how to to update the Quantity displayed in a txtQuantity. How do i code a 'btnUpdate' so that it will read the txtQuantity and update each row of item's quantity according to the txtQuantity.Text. The code should update to the datatable and display on updated value on the txtQuantity after button has been clicked, this is my code for the display of shopping cart items in a repeater. <%# Container.DataItem("Product") %> td><%# Container.DataItem("Code") %> <%# Double.Parse(Container.DataItem("Cost")).ToString("C") %> Remove Header Codes: Dim dtCart As DataTable Dim drCart As DataRow dtCart = Session("Cart") viewCart.DataSource = dtCart.DefaultView viewCart.DataBind()