i am Creating visulaForce page which shows selected opportunity
but my code is not working it not shows  selected opp
iam unable to find out where is the mistake
Help should be appriciated. Thank You
Here is my code :
<apex:page standardController="Opportunity" recordSetVar="Opps"  sidebar="false" showHeader="false" 
                                      extensions="ParamReceive" >
<apex:form>
    <apex:pageBlock>
        <apex:pageBlockSection>
           <apex:pageBlockTable value="{!Opps}" var="o" id="panel">
             <apex:column>
                 <apex:inputCheckbox>
                     <apex:actionSupport event="Onclick" action="{!doActionSupport}"  reRender="block,panel">
                     <apex:param name="names" value="{!o.Id}" assignTo="{!vfParam}" />
</apex:actionSupport>
                 </apex:inputCheckbox>
             </apex:column>
             <apex:column value="{!o.Name}"/>
             <apex:column value="{!o.stageName}"/>
             <apex:column value="{!o.CloseDate}"/>
             <apex:column value="{!o.Amount}"/>
             <apex:column value="{!o.AccountId}"/>
          </apex:pageBlockTable>
          <apex:outputPanel id="block">
          
          Selected Opportunity  : {!vfParam}<br></br>
        </apex:outputPanel>
        
        </apex:pageBlockSection>
    </apex:pageBlock>
</apex:form>
</apex:page>

Controller:
public  class ParamReceive {
        public String vfParam{get; set;}
        public ParamReceive(ApexPages.StandardSetController controller){
          
        }
        public PageReference doActionSupport(){
          // Do Something...
          System.debug('vfParam : ' + vfParam);
          return null;
        }
    }