var objAjax;

        function getHTTPObject(){
                if(window.XMLHttpRequest){
                        return new XMLHttpRequest();
                } else
                if(window.ActiveXObject){
                        var prefixes = ["MSXML2", "Microsoft", "MSXML", "MSXML3"];
                        
                        for(var i = 0; i < prefixes.length; i++){
                                try{
                                    return new ActiveXObject(prefixes[i] + ".XMLHTTP");
                                } catch (e) {}
                        }
                }
        }

        function ativaSelecao( oObj, oId ){
                objAjax = getHTTPObject();
                objAjax.onreadystatechange = retornoAtivacao;
                objAjax.open("GET","selecao-acao.php?id=" + oId, true);
                objAjax.send(null);
        }

        function retornoAtivacao(){
                if (objAjax.readyState == 4){
                        if( objAjax.responseText == "true" ){
                                selecaoAnterior = "img/estrela-amarela.gif";
                        }
                        else{
                                selecaoAnterior = "img/estrela-cinza.gif";
                                if( selecao == "sim" ) {
                              	history.go(0); 
                              	}
                        }
                }
        }