for counter=0 to 1000
  work = arrayFileInhalt (counter)
 
  RichTextBox1.SelectedText=work+vbCrLf;  
  if instr(1,work,"MSG") >0 then
    RichTextBox1.SelectionFont= new Font(RichTextBox1.SelectionFont, _
      FontStyle.Bold)
  end if
next counter