ASP.NET error message

Question

  The code listed below only works on the line, "string id = ((TextBox)DetailsView1.FindControl("TextBoxAttid")).Text;" regardless of the order I place the lines of code.

When I step through code and get to the other lines of code, I get the error message

"Object is not set to an instance of the object". The only object I think this error is referring to is the detailsview object. However that is not the error.

Thus can you tell me what object the code wants a new instance of?

if (DetailsView1.CurrentMode == DetailsViewMode.ReadOnly)
  {
  string id = ((TextBox)DetailsView1.FindControl("TextBoxAttid")).Text;
  }
  else if (DetailsView1.CurrentMode == DetailsViewMode.Edit)

  {
  string name1 = ((TextBox)DetailsView1.FindControl("TextBoxAttid")).Text; 
  string  name3 = ((TextBox)DetailsView1.FindControl("Invalid_Form")).Text; 
  string name2 = ((TextBox)DetailsView1.FindControl("Prior_Cutoff_Date")).Text;

  }