function openWin(img) {
  winId = window.open('','newwin','width=700,height=600');
  winId.document.write('<body marginheight="25" topmargin="25" leftmargin="5" marginwidth="0" rightmargin="0" bottommargin="0" onLoad="if (window.focus) window.focus()"><center>');
  winId.document.write('<img src="' + img + '" vspace="5">');
  winId.document.write('<form><input type=button value="dit venster sluiten" onClick=self.close()></form>');
  winId.document.write('</center></body>');
  winId.document.close();
}
