Object reference not set to an instance of an object.

 Hi,

I am trying to access the content of textboxes by from the previous page.  I used several methods but fails. Only i am receiving error "Object reference not set to an instance of an object".

1.  The first method i used , it fails.

 Dim txtSearch As TextBox = CType(PreviousPage.FindControl("txtSearch"), TextBox)
 lblSearch.Text = String.Format("Search For: {0}", txtSearch.Text)

2.  I used viewstate for storing textboxes text and trying to access in the next page, same problem.

3. I used to store the details in one page as:

Public ReadOnly Property SearchString() As String
        Get
            Return txtSearch.Text
        End Get
    End Property


And to access the above ...