I am trying to learn Javascript and happened across the video "PHP & Form Validation". All works except the phone number field. It is set as required and to be formatted as 000-000-0000. If it's left blank I get a message "This field is required". Then if I go back and enter just 1 digit it's accepted, instead of saying "Please enter a valid phone number". I have no idea what could be wrong or where to start looking to fix the issue. Can someone please suggest things to checked. I want to fix it myself, so just some tips on what to check will be greatly appreciated. Thank you