checkValidity not triggering on form

I've created a Form in HTML and I've added the required tag to each field but the validity check doesn't seem to recognize there's no input so my script just hangs. Below is the script to check validity;

$("#savechanges").Click(function() 
  {
  valid = "";
  if ($("#form")[0].checkValidity()) 
    {
    valid = "Y";
    insertrecord();
    }
  else 
    {
    $("#form")[0].reportValidity()
    }
  });"

I've checked to see if everything is within the tag and it all looks ok, I've duplicated the above script from another page where it works so I'm unsure what's going wrong or where to look.

Originally I thought it was some custom CSS which was blocking the "Please fill in this field" but I removed it from the file so it was just a plain form but it still doesn't trigger