Login form issue vb.net - vb.net

Question

I'm creating a student data management system and I'm stuck on the login form.
I've created a sign up form where the details entered are saved in a text file (Users.txt).
I can't seem to figure out what the problem is in the login form code (pasted below); it doesn't seem to recognise any saved login usernames and passwords.
Please help.
Thanks.
Imports System.IO
Public Class Registration
Dim myfilewriter As StreamWriter
Dim myfilereader As StreamReader
Dim strMyFilename As String
Dim intNumofRecs As Integer
Dim temp As String
Structure Users
Dim intUserID As Integer
Dim strusername As String
Dim strpassword As String
End Structure
Dim UsersArray() As Users
Private Sub readindata()
Dim intCounter As Integer
strMyFilename = "Users.txt"
myfilereader = New StreamReader(strMyFilename)
intNumofRecs = myfilereader.ReadLine
ReDim Preserve UsersArray(intNumofRecs)
intCounter = 0
Do Until myfilereader.EndOfStream = True
intCounter = intCounter + 1
UsersArray(intCounter).intUserID = myfilereader.ReadLine()
UsersArray(intCounter).strusername = myfilereader.ReadLine()
UsersArray(intCounter).strpassword = myfilereader.ReadLine()
Loop
myfilereader.Close()
End Sub
Private Sub btnNewUser_Click(sender As Object, e As EventArgs) Handles btnNewUser.Click
Me.Hide()
Sign_Up.Show()
End Sub
Private Sub Registration_Load(sender As Object, e As EventArgs) Handles MyBase.Load
readindata()
End Sub
Private Sub btnLogin_Click(sender As Object, e As EventArgs) Handles btnLogin.Click
Dim username As Boolean = False
Dim password As Boolean = False
Dim temp As String
myfilereader = System.IO.File.OpenText("Users.txt")
temp = myfilereader.ReadToEnd
myfilereader.Close()
If txtusername.Text = temp And txtpassword.Text = temp Then
username = True
password = True
Else
MsgBox("User not found")
End If
If username And password = True Then
txtusername.Text = ""
txtpassword.Text = ""
Me.Hide()
Dashboard.Show()
Else
End If
End Sub
End Class
and below is the code for the sign up form (how the text is saved to the users.txt file):
Public Sub SavetoTextFile()
Dim intCounter As Integer
readindata()
intNumofRecs = intNumofRecs + 1
ReDim Preserve UsersArray(intNumofRecs)
UsersArray(intNumofRecs).intUserID = intNumofRecs
UsersArray(intNumofRecs).strusername = txtUsername.Text
UsersArray(intNumofRecs).strpassword = txtPassword.Text
strMyFilename = "Users.txt"
myfilewriter = New StreamWriter(strMyFilename)
myfilewriter.WriteLine(intNumofRecs)
For intCounter = 1 To intNumofRecs
myfilewriter.WriteLine(UsersArray(intCounter).intUserID)
myfilewriter.WriteLine(UsersArray(intCounter).strusername)
myfilewriter.WriteLine(UsersArray(intCounter).strpassword)
Next
myfilewriter.Close()
End Sub
Private Sub btnSignUp_Click(sender As Object, e As EventArgs) Handles btnSignUp.Click
SavetoTextFile()
txtUsername.Text = ""
txtPassword.Text = ""
Me.Hide()
Registration.Show()
End Sub