dynamically creating the Control increasing my Memory usage

hi
when I create the Controls dynamically, the memory usage getting incrase and incrase. Memory not getting dispose.
How to dispose the dynamacally created controls?

For example In my application I have one drpdown Control.
on page Init I am loading this drpdown dynamically.
like this:
    Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        Dim PST As Integer = 1
        Dim PFor As Char = "S"
        Dim i As Integer = 0
        For i = 0 To 1
            Dim Regionlstitm As ListItem
            Regionlstitm = New ListItem(i.ToString(), i.ToString())
      &n ...