How to tell script colse all files and save, but no untitle docs

Question

Hi everyone 
I want to colse the open files and save them but no those files which have never been saved.
I try this script but after ran, all the files are no be saved.
        var docs = app.documents;
             for (var i = docs.length-1; i >= 0; i--) {
                 if(app.activeDocument.saved == false){
                       docs[i].close(SaveOptions.NO);
                 else if(docs[i].close(SaveOptions.YES));
can someone tell me what's wrong with the script?
thanks
Regard
Teetan

Answer 1

var docs = app.documents;
for (var i = docs.length-1; i >= 0; i--) {
    if (docs[i].saved == false) {
        docs[i].close(SaveOptions.NO);
    else {
        docs[i].close(SaveOptions.YES);