Takayuki,
when I add the "*" to the select clause to mark it as required, it breaks the clause.
[response]
<p>Your Name (required)<br />[text* your-name] </p>
<p>Your Email (required)<br />[email* your-email] </p>
<p>Your Country (required)<br /><select* class="wpcf7-form-control wpcf7-select wpcf7-validates-as-required wpcf7-validates-as-text" id="country" name="country" onchange="print_state('state',this.selectedIndex);" id="country" name = "country"></select> </p><p>Your State (required)<br />
<select* class="wpcf7-form-control wpcf7-select wpcf7-validates-as-required wpcf7-validates-as-text" name ="state" id = "state"></select>
<script language="javascript">print_country("country");</script></p>
<p>Subject<br />[select* topic "General" "Sales" "Training" "Support" "Licensing" "Customer Care"] </p>
<p>Your Message<br />[textarea your-message] </p>
<p>[submit "Send"]</p>
Thanks for your help