gistfile1.txt

                                Dim vorname As String = register_vorname.Text
                                Dim nachname As String = register_nachname.Text
                                Dim email As String = register_email.Text
                                Dim PW As String = register_pw1.Password
                                Dim verfuegbar As Boolean = False

                                SQL = "SELECT `vorname` FROM `benutzer`"

                                Command.Connection = MySQL
                                Command.CommandText = SQL
                                Adapter.SelectCommand = Command
                                Data = Command.ExecuteReader()
                                Do While Data.Read

                                    If vorname = Data("vorname") Then
                                        verfuegbar = False
                                    Else
                                        verfuegbar = True
                                    End If

                                Loop

                                If verfuegbar = True Then
                                    SQL = "INSERT INTO `benutzer` (`vorname`, `nachname`, `email`, `password`) VALUES ('" & vorname & "', '" & nachname & "', '" & email & "', '" & PW & "');"
                                    MsgBox(SQL, 32)
                                Else
                                    MsgBox("Der Name ist bereits vergeben!", vbExclamation)
                                End If

                                Data.Close()
                                MySQL.Close()