Postgres 9.3 backup restore vb.net

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VB

PostgreSQL

I have a postgres db 9.3 which i need to do a manual backup from the front end .
It seems to work but the dump files are always 0kb and cannot be used for restore:

Sub executeCommand(ByVal commandType As String, ByVal commandSentence As String)
        Try
            Dim info As New ProcessStartInfo()
            info.FileName = Application.StartupPath & "\Reports\" + commandType + ".exe "
            info.Arguments = commandSentence
            info.CreateNoWindow = True
            info.UseShellExecute = False
            proc.StartInfo = info
            proc.Start()
            proc.WaitForExit()
            If commandType = "pg_dump" Then
                KryptonLabel1.Text = "Backup successfully created"
            ElseIf commandType = "pg_restore" Then
                KryptonLabel1.Text = "Restore successfully executed"
            End If


        Catch ex As Exception
            KryptonLabel1.Text = ex.ToString()
        End Try

    End Sub

Private Sub KryptonButton4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles KryptonButton4.Click
    '-W  " + password + "
    Dim xxx As String = "-i -h  " & hostName & "  -p  " & strPort & " -U " & userName & " --no-password -F c -b -v  -f " & Label2.Text & " " & txtDB
    ' xxx = " -U postgres -h 127.0.0.1 -p 5432 -F p -f F:\FileName1.backup -w postgres"
    executeCommand("pg_dump", xxx)
End Sub