write something into form1 textbox from component

[bafidi]

hi i want help
my component is

Public Class frmYeniGirisGenelComponent
Inherits System.ComponentModel.Component

Public Sub deneme()
Dim YeniGiris As ARAMA.frmYeniGiris
YeniGiris.txtOfTaKonu.Text = "1985"

End Sub
End Class
my solution name is ARAMA
form name is frmYeniGiris
button name btnTemizle

when i press button it call deneme sub then deneme sub write textbox 1985

but i take this err message

An unhandled exception of type 'System.NullReferenceException' occurred in
ARAMA.exe

Additional information: Object reference not set to an instance of an object.