jsf+ajax问题

<html><head><script type="text/javascript" src="/a4j/a4j.res/org.ajax4jsf.framework.ajax.AjaxScript">
</script><style type="text/css"><!--
.px10{
padding-bottom: 10px;
}
-->
</style><title>a4j-support with Selects</title></head><body><form id="_id1" method="post" action="/a4j/pages/demo.jsf"
 enctype="application/x-www-form-urlencoded"><span id="_id0:status.start" 
 style="font-color:red; display: none">Request under process</span
 ><span id="_id0:status.stop">Ready
 </span><span style="display:block;font:italic">There you can choose some simple parameters of vehicle, all the changes will be processed with AJAX requests (All changes applies in AJAX mode)</span><span style="display:block">Choose a vechycle type:</span><span class="px10" style="display:block;"><select name="_id1:_id6" size="1" onchange="A4J.AJAX.Submit('_id0','_id1',event,{'parameters':{'_id1:_id9':'_id1:_id9'},'actionUrl':'/a4j/pages/demo.jsf','control':this,'single':true})"><option value="car">Car</option><option value="motorcycle" selected="selected">Motorcycle</option></select></span>Choose an engine type:(Different value sets with car and moto)<span id="_id1:Option1" class="px10" style="display:block"><select name="_id1:_id11" size="1" onchange="A4J.AJAX.Submit('_id0','_id1',event,{'parameters':{'_id1:_id13':'_id1:_id13'},'actionUrl':'/a4j/pages/demo.jsf','control':this,'single':true})"><option value="250" selected="selected">250 cubic centimeters</option><option value="500">500 cubic centimeters</option><option value="750">750 cubic centimeters</option></select></span>Choose a body type(Only sport Type for Highest engines):<span id="_id1:Option2" class="px10" style="display:block"><select name="_id1:_id15" size="1" onchange="A4J.AJAX.Submit('_id0','_id1',event,{'parameters':{'_id1:_id17':'_id1:_id17'},'actionUrl':'/a4j/pages/demo.jsf'})"><option value="classic" selected="selected">Classic</option><option value="sport">Sport</option></select></span><input type="text" name="_id1:_id18" value="" onkeyup="A4J.AJAX.Submit('_id0','_id1',event,{'parameters':{'_id1:_id19':'_id1:_id19'},'actionUrl':'/a4j/pages/demo.jsf'})" size="50"><span id="_id1:rep"></span><input id="_id1:_id20" name="_id1:_id20" onclick="A4J.AJAX.Submit('_id0','_id1',event,{'parameters':{'_id1:_id20':'_id1:_id20'},'actionUrl':'/a4j/pages/demo.jsf'});return false;" value="Show me My Choise" type="button"><span id="_id1:summary" style="font:large;">You've choosen motorcycle with 250 value engine and classic body variant</span><input type="hidden" name="_id1" value="_id1"></form></body></html>