This exemple is pretty simple, use it to get you started.
<?php $wnd= dhtml_create(); $stop= FALSE; while(!$stop) { $evt= dhtml_get_event(1); echo "Event $evt->id, $evt->type, $evt->value, $evt->extra\n"; switch( $evt->type ) { case 'event_close': dhtml_set( $wnd, "close" ); $stop= TRUE; break; case 'init': dhtml_set( $wnd, "show", "1"); dhtml_set($wnd, "load_default"); // Load a default empty page dhtml_set( $wnd, "title", "php_dhtml example"); break; case 'page_load': $html= '<DIV align="center"><TABLE id="Table1" cellspacing="1" cellpadding="1" width="300" border="1" align="center"><TR><TD width="124">Name:</TD><TD><INPUT id="nom" type="text" name="name"></TD></TR><TR><TD width="124">Age:</TD><TD><INPUT id="age" type="text" ame="age"></TD></TR><TR><TD colspan="2" align="center"><INPUT type="button" value="OK" ID="OK"></TD></TR></TABLE></DIV><DIV align="center"> </DIV><HR width="100%" SIZE="1"><P id="result" align="center"></P>'; dhtml_set( $wnd, "id_html", "body", $html); dhtml_set( $wnd, 'event_click', 'OK' ); break; case 'event_click': switch( $evt->value ) { case 'OK': $age= dhtml_get( $wnd, 'id_value', 'age'); $nom= dhtml_get( $wnd, 'id_value', 'nom'); if( !empty($age) && !empty($nom) ) { dhtml_set( $wnd, 'id_value', 'nom', '' ); dhtml_set( $wnd, 'id_value', 'age', '' ); dhtml_set( $wnd, 'id_html', 'result', "Hello $nom you are $age years old" ); } else dhtml_set( $wnd, 'id_html', 'result', "Please fill all fields" ); break; } break; } } ?>