How can I go about adding a parameter to a datasource at runtime? I am using VB as code. Here is what I have but it doesnt work.

VB Code:
  1. Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
  2.         If Not TextBox1.Text = "" Then
  3.             AccessDataSource2.SelectParameters.Add("City", TextBox1.Text)
  4.         End If
  5.         AccessDataSource2.DataBind()
  6.     End Sub

City is the column name in the database.
Thanks!