Form Validation Error Messages Javascript

i am working for my application module:a. Form will consist of two input how to display error message in javascript without using alert fields (name and email) and a submit button.b. On submit, how to display error message beside textbox using javascript the validation should check if the fields are empty.c. If any field is empty, the form validation in javascript with error messages examples text colour as well as border of the field should turn red. (No need to show an error message)d. When I start typing in the how to display error message in html using javascript field, The text and border colour should return to default colour. Below is the code which i had tried: