Refresh ListBox Control During Loop

Using ASP.NET and VB.NET code behind, I have the following code:
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim I As Integer = 0
For I = 0 To 10
ListBox1.Items.Add(I)
ListBox1.DataBind()
System.Threading.Thread.Sleep(300)
Next
End Sub
The intended output of the code is to update the listbox1 control at each iteration, but what really happens is it updates the listbox1 control after the entire loop finishes..Is there a way to update the listbox1 control as its intended by the code logic?