Preinit event says server Control not referenced if used in Master/Content pages

[Rahul]

this is my code in preinit event
I have "hlinkAdd" as hyperlink web control and i am using a master page, and
below code is of content page preinit event.

Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Me.PreInit
If Request.QueryString("process") = "" Or
Request.QueryString("process") = "Add" Then
hlinkAdd.SkinID = "up" (error is thrown here Object reference
not set to an instance of an object)
hlinkAdd.NavigateUrl = ""
trCompanyName.Visible = False
ElseIf Request.QueryString("process") = "Edit" Then
'LinkEdit.ForeColor = Drawing.Color.Aqua
hlinkEdit.SkinID = "up"
hlinkEdit.NavigateUrl = ""
cmbCompanyName.AutoPostBack = True
trCompanyName.Visible = True
End If
End Sub

I get the following error ....


Please help me ...

Rahul