Visual Basic

Imports System.Text.RegularExpressions
.
.
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Public Shared Function EmailAddressIsValid(ByVal address As String) As Boolean
   Dim strRegex As String = "^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}" & _
                            "\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\" & _
                            ".)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$"
   Dim re As New Regex(strRegex)
   If re.IsMatch(address)
        Return True
    Else
        Return False
End Function

<br />
Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click<br />
Dim objRegEx As New System.Text.RegularExpressions.Regex("^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$")<br />
    If objRegEx.IsMatch(TextBox1.Text) Then<br />
        ErrorProvider1.SetError(sender, "")<br />
    Else<br />
        ErrorProvider1.SetError(sender, "Email address is not valid")<br />
    End If<br />
End Sub<br />

Public b1 As Bitmap
Public g1 As Graphics

b1 = New Bitmap(Width, Height, Panel1.CreateGraphics())
g1 = Graphics.FromImage(b1)
g1.SmoothingMode = Drawing2D.SmoothingMode.AntiAlias

<br />
Private Sub CreateTextFile(ByVal FilePath As String, ByVal data As String)<br />
        Dim oFile As System.IO.File<br />
        Dim oWrite As System.IO.StreamWriter<br />
        Dim oRead As System.IO.StreamReader<br />
        Dim PreviousData As String = ""<br />
       <br />
<br />
        If File.Exists(FilePath) Then<br />
            oRead = oFile.OpenText(FilePath)<br />
            While oRead.Peek <> -1<br />
                If PreviousData = "" Then<br />
                    PreviousData = oRead.ReadLine()<br />
                Else<br />
                   <br />
                    PreviousData = PreviousData & ControlChars.NewLine & oRead.ReadLine<br />
                <br />
                End If<br />
            End While<br />
            oRead.Close()<br />
        End If<br />
<br />
        oWrite = oFile.CreateText(FilePath)<br />
<br />
        If PreviousData = "" Then<br />
            PreviousData = data<br />
            oWrite.WriteLine(PreviousData)<br />
        Else<br />
            PreviousData = PreviousData & ControlChars.NewLine & data<br />
            oWrite.WriteLine(PreviousData)<br />
        End If<br />
        <br />
        oWrite.Close()<br />
end sub