how to make inputBox's ok and [Enter] key press make it pop up again with a loop - vb.net

Question

The main question is: how can i make InputBox keep poping up when the user either clicks Ok or presses [Enter] on the keyboard? This program stores each value in a sequential access file.
Option Explicit On
Option Strict On
Option Infer Off
Public Class frmMain
Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
End Sub
Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
Dim outFile As IO.StreamWriter
Dim strInput As String
Dim dblInput As Double
'Do
strInput = InputBox("Enter A Number", "Test Scores Project")
Double.TryParse(strInput, dblInput)
outFile = IO.File.CreateText("Scores.txt")
outFile.WriteLine(dblInput)
'While user presses the enter button or ok keep asking for more numbers
outFile.Close()
Me.Close()
End Sub
Private Sub btnCount_Click(sender As Object, e As EventArgs) Handles btnCount.Click
Dim inFile As IO.StreamReader
Dim strMessage As String
Dim intFiles As Integer
If IO.File.Exists("Scores.txt") Then
inFile = IO.File.OpenText("Scores.txt")
Else
MessageBox.Show("No such file exists", "Text Scores Project")
End If
Do Until inFile.Peek = -1
strMessage = inFile.ReadLine
intFiles += 1
Loop
lblNumber.Text = intFiles.ToString
End Sub
End Class

Answer 1

Try initializing outfile in the declaration:
Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
Using outFile As New IO.StreamWriter("Scores.txt")
Dim strInput As String
Dim dblInput As Double
Do
strInput = InputBox("Enter A Number(done when finished)", "Test Scores Project")
If Double.TryParse(strInput, dblInput) Then
outFile.WriteLine(dblInput)
End If
While strInput <> "done"
End Using
Me.Close()
End Sub
A simple while loop will work here.
Note: The use of the Using block. This handles all the clean up of the stream.

Answer 2

The reason you're getting that warning about inFile is because the compiler recognizes that the code path could go through the Else branch of If IO.File.Exists("Scores.txt") without ever assigning a value to inFile.
Try doing this: Dim inFile As IO.StreamReader = Nothing