You try adding a scrip tag in your jsp code, and calling the function in the onclick attribute.
Example:
<script><![CDATA[
function confirmDelete(){
if(confirm("Are you sure you want to delete selected user")){
return true;
} else{
return false;
}
}
]]></script>
<ui:button action="#{View.delete_action}" binding="#{View.delete}" id="delete" onclick="confirmDelete"/>
Cheers
Daniel
null