inserttext to textarea :-)

function display_bbcodes($width,$id) {
 global $bb_cache;
echo "<script type='text/javascript' src='".BASEDIR."add.js'></script>";
if (!$bb_cache) { bb_input(); }
if (is_array($bb_cache) && count($bb_cache) > 0) {
echo "<div width='".$width."'>"; 
  foreach($bb_cache as $bb) {
echo "<button onclick=\"AddItem('".$bb['bb_start'].$bb['bb_end']."','".$id."');\">".$bb['bb_tag']."</button>";     
  }
echo "</div>"; 
}
}

<script language="JavaScript" type="text/JavaScript">
function AddItem(ItemId,ID)
{
document.Form.document.getElementById(ID).value = document.Form.document.getElementById(ID).value + '<' + ItemId;
}

</script>

echo "Popis:</td><td><textarea name='popis' rows='5' cols='50' id='bb'>".$popis."</textarea></td></tr>";
  echo "<tr><td>".display_bbcodes("150","bb")."</td></tr><tr><td>";