selected =new List<SelectOption>();
    unselected = new List<SelectOption>();
   /// set1=new set<SelectOption>(optionsList());
    list1.addAll(optionsList());

}

public List<SelectOption> optionsList(){
    system.debug('im in');
    Schema.DescribeSObjectResult result = Account.sObjectType.getDescribe();
    List<Schema.ChildRelationship> childs = result.getChildRelationships();
    List<SelectOption> options = new List<SelectOption>();

    for(Schema.ChildRelationship s: childs){
        string str = String.valueOf(s.getRelationshipName());
        options.add(new Selectoption(str,str));
        system.debug(options);
    }
    system.debug('---------out------' + options);
    return options;
}

public void doAdd(){

}

public void doRemove(){

}