Introduction: HTML Required Fields
If you want to make your form fields required so that the browsers stops a user from submitting empty fields, then the "required" attribute is for you. It is supported on most modern browsers and full support information can be found at http://caniuse.com/#feat=form-validation
Step 1: Locate Your HTML Form
Find the file with the HTML form you want to edit and open it in your favorite text editor.
Step 2: Add the "required" Attribute
Add the "required" attribute to each field that you want to be required.
Step 3: Refresh Your Page and Test
And you are done! Remember to make sure that the browsers your users have supports this by checking the compatibility at http://caniuse.com/#feat=form-validation