<apex:page standardController="Webinar__c" extensions="CheckAllUsingJavascriptController" sidebar="false">
<apex:form >

      <apex:pageBlock >
        <apex:outputLabel > Countries : </apex:outputLabel>
        <apex:selectList size="1" value="{!selectedCountry}">
          <apex:selectOptions value="{!countrieLst }"/>
        </apex:selectList> <br/>
    </apex:pageBlock>
  </apex:form>
</apex:page>

public List<wrapAccount> wrapperAccountList {get; set;}
 public List<System.SelectOption> countrieLst {get;set;}
 public String selectedCountry{get;set;}

List<Lead> LeadList = new List<Lead>();

public CheckAllUsingJavascriptController (Apexpages.StandardController stdcController){
//List<LightiningEd__Webinar_Attendees_Status__c> selectedContacts = new List<LightiningEd__Webinar_Attendees_Status__c>();
 countrieLst = new List<System.SelectOption>();
    if(wrapperAccountList == null) {
        wrapperAccountList = new List<wrapAccount>();

        for(LightiningEd__Webinar__c a1: [select id,Name,Start_Time__c,Finish_Time__c,Registration_URL__c,Expired__c,SCO_ID__c,Retrival_Date__c,(select id,Name,principal_id__c,Login__c,isLead__c,Attandance_Status__c,Duration_Spend__c,Company_Name__c,City__c,State__c,Country__c,Mobile_Phone__c from LightiningEd__Webinar_Attendees_Statuss__r) from LightiningEd__Webinar__c where id = :ApexPages.currentPage().getParameters().get('id')]) {
            for(LightiningEd__Webinar_Attendees_Status__c a : a1.LightiningEd__Webinar_Attendees_Statuss__r){

                   wrapperAccountList.add(new wrapAccount(a));

            }
        }
    }
}

public PageReference processSelected(){

List<LightiningEd__Webinar_Attendees_Status__c> selectedContacts = new List<LightiningEd__Webinar_Attendees_Status__c>();
 countrieLst = new List<System.SelectOption>();
     //countryOptions = new List<System.SelectOption>();
for(wrapAccount cCon: wrapperAccountList){
    if(cCon.selected == true){

        selectedContacts.add(cCon.acc);

    }
}

System.debug('These are the selected Contacts...'+selectedContacts);
for(LightiningEd__Webinar_Attendees_Status__c acc : selectedContacts){

    system.debug('selected records::::'+acc);

     countrieLst.add(new System.SelectOption(acc.Name,acc.Name));
     countrieLst.add(new System.SelectOption(acc.LightiningEd__Login__c,acc.LightiningEd__Login__c));
     countrieLst.add(new System.SelectOption(acc.LightiningEd__Attandance_Status__c,acc.LightiningEd__Attandance_Status__c));
     countrieLst.add(new System.SelectOption(acc.LightiningEd__Company_Name__c,acc.LightiningEd__Company_Name__c));
     countrieLst.add(new System.SelectOption(acc.LightiningEd__City__c,acc.LightiningEd__City__c));
     countrieLst.add(new System.SelectOption(acc.LightiningEd__State__c,acc.LightiningEd__State__c));
     countrieLst.add(new System.SelectOption(acc.LightiningEd__Country__c,acc.LightiningEd__Country__c));
     countrieLst.add(new System.SelectOption(acc.LightiningEd__Mobile_Phone__c,acc.LightiningEd__Mobile_Phone__c));

    System.debug('CountryOptions:::'+countrieLst);
    //countryOptions1.addAll(countryOptions);


}

wrapperAccountList=null;
return null;

public class wrapAccount {

    public LightiningEd__Webinar_Attendees_Status__c acc {get; set;}
    public Boolean selected {get; set;}
    public wrapAccount(LightiningEd__Webinar_Attendees_Status__c a) {
        acc = a;
        selected = false;
    }
}