Express.js: Validation of forms with text boxes and buttons

I am working with forms in Express.js and I am using express-validator for validation. The code I have shown below is a "form" with two text boxes, a choose file button and a submit button. When the user submits the form, but there are validation errors I would like to:

1. Show an error message, saying which of the elements in the form the user needs to fill in. I believe I know how to do this with pop-up windows, but I would like to know if there is a way to "highlight" the text box that the user is required to fill in, or put a "* Required" text next to the text box/button.

2. Currently, if there are errors, after the submission, the two text boxes in the form are populated with the variables that were previously submitted by the user. I would like to do the same thing for the "Choose file" button. Using the "value" field as I have done in the two text boxes, does not work for the button. Is there way to do this?

//in routes folder

exports.myPage = function(req, res) {
   res.render('myPage.jade', {valName: 'Enter', valLastName: 'Enter'});
};

exports.myPage_post_handler = function(req, res) {

   nameID = req.body.nameID;
   lastNameID = req.body.lastNameID;
   my_file = req.body.my_file;

   req.session.nameID = nameID;
   req.session.lastNameID = lastNameID;
   req.session.my_file = my_file;

   if (typeof req.session.nameID != 'undefined'){
      valName = nameID;
   }

   if (typeof req.session.lastNameID != 'undefined'){
      valLastName = lastNameID;
   }


   req.assert('nameID', 'Please enter a name').notEmpty();
   req.assert('lastNameID', 'Please enter a last name').notEmpty();
   req.assert('my_file', 'Please enter a my_file').notEmpty();



   var errors = req.validationErrors();

   if( !errors){
     res.redirect('/other_page'); 
   }
   else {
     res.render('myPage.jade');
   }
 };

 //in my_page.jade
 form(method='post')
    | Name:
    div
     input(type='text', name='nameID', id = 'name', value = valName)
    | Session ID:
    div
     input(type='text', name='laastNameID', id ='lastName', value = valLastName)
    | Video:
    div
     input(type='file', name='my_file', id='fileF')

    div
     input(type='submit', value='submit', value='Submit')