How to add two edit text fields in an alert dialog

I am trying to use an alert dialog to prompt for a username and a password in android. I have found this code here:

  if (token.equals("Not Found"))
    {
        LayoutInflater factory = LayoutInflater.from(this);            
        final View textEntryView = factory.inflate(R.layout.userpasslayout, null);

        AlertDialog.Builder alert = new AlertDialog.Builder(this); 

        alert.setTitle("Please Login to Fogbugz"); 
        alert.setMessage("Enter your email and password"); 
        // Set an EditText view to get user input  
        alert.setView(textEntryView); 
        AlertDialog loginPrompt = alert.create();

        final EditText input1 = (EditText) loginPrompt.findViewById(R.id.username);
        final EditText input2 = (EditText) loginPrompt.findViewById(R.id.password);

        alert.setPositiveButton("Login", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int whichButton) { 
            input1.getText().toString(); **THIS CRASHES THE APPLICATION**


        } 
        }); 

        alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, int whichButton) { 
            // Canceled. 
          } 
        }); 

        alert.show(); 

    }

EDIT: I was able to set up the proper layout, but receive an error when I try to access the text field. What is the problem here?