Comparing two variables

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    Dim lineNumber0 As Integer
    Dim mass As Double
    Dim input As Double

    If Double.TryParse(File.ReadAllLines("225.txt").ElementAt(linenumber0), mass) Then
        If Double.TryParse(TextBox1.Text, input) AndAlso Math.Abs(input - mass) < 0.5 Then
            TextBox1.BackColor = Color.Green      
    Else
        textbox1.backcolor=color.red
    End If
   End if