Thank you all,<br>It's quite simple with the keyword and Axel's example :).<br>Have a nice weekend,<br><br><br clear="all"><br>-- <br>Nguyen, Ngoc Ha<br>Hanoi National University of Education<br>Faculty of Chemistry<br>
Department of Physical Chemistry<br>Tel: Office: 04/38330842<br>Home: 04/37891674<br>Mobile: 0989133436<br><a href="mailto:E-mail...@hnue.edu.vn">E-mai...@hnue.edu.vn</a><br>