How to apply post redirect and get pattern in node.js?

I am testing with a very simple application in node.js where I create and save an application. I show the post form with the newPost function and I receive the post with the data in the savePost method. In the latter one I do a validation (with iform module) and I want to go show again the same page as before but filling the form with the data sent by the user and also with the errors found.

I have a similar code like this one. In it I render the same jade page if I find any error. It works though I want to apply the pattern redirect and get there as I don't want to send again the post request when the user presses F5.

So, how is the usual way to make a post redirect and get from the post method passing them all the parameters I have received adding the errors? Is there any module which can help to do so?

var prepareObject = function(req, res){
    var errors = {};
    if('iform' in req){
        errors = req.iform.errors;
    }
    return {title: 'Nuevo Post', body:req.body, errors: errors};
};

// mapped as /newPost (type GET)
exports.newPost = function(req, res){
    //show form to create post
    res.render('newPost', prepareObject(req, res));
}

// mapped as /savePost (type POST)
exports.savePost = function(req, res){
    if(req.iform.errors) {
        //there are errors: show form again to correct errors
        res.render('newPost', prepareObject(req, res));
    }else{
        //no errors: show posts
        res.redirect('/posts');
    }   
}