Read And Loop Through Text File?

I am writing a VB.NET program and I'm trying to accomplish the following:
Read and loop through a text file line by line
Show the event of the loop on a textbox or label until a button is pressed
The loop will then stop on any number that happened to be at the loop event and when a button is pressed again the loop will continue.

Code
Imports System.IO
Public Class Form1
'Dim nFileNum As Integer = FreeFile() ' Get a free file number
Dim strFileName As String = "C:scb.txt"
[Code] .....

I'm able to read the text file but my label will only loop if I hit the start button. It goes to the next line, but I want it to continue to loop through the entire file until I hit a button telling it to stop.