Here is how to do it for people who had the same problems
Code:
Private Sub Enabletextboxs()
' Find control on page.
' I used txtStart to get the parent because its on an ascx
Dim mycontrol1 As Control = FindControl("txtStart")
Dim mycontrol2 As Control = myControl1.Parent
For Each mycontrol1 In mycontrol2.Controls
'"System.Web.UI.WebControls.ListBox"
Dim tmp As String = mycontrol1.GetType().FullName
If tmp = "System.Web.UI.WebControls.TextBox" Then
CType(mycontrol1, TextBox).Enabled = True
End If
Next
End Sub