Cannot find control - BC30451: Name 'frvReminder2' is not declared

I've used this code in another page and it works fine. But it doesn't work on another page where the asp:formview ID="frvReminder2" is nested in an asp:Listview control (id=lvCourses)
How can I rewrite this so I it will recognize frvReminder2 when it's nested in the Listview control?
Protected Sub btnSend_Click(ByVal sender As Object, ByVal e As System.EventArgs) Dim course As Label = TryCast(frvReminder2.FindControl("CourseTitleLabel"), Label) Dim sdate As Label = TryCast(frvReminder2.FindControl("StartDateLabel"), Label) Dim weeks As CheckBox = TryCast(frvR ...