Modal Form Please fill out this field warning only appear in Chrome but not Safari?

I have a Modal form,when i opened in Chrome when i click sign-in without putting in any fields, it gives me a warning- please fill in all fields, but when i open it in Safari and i click sign-in without filling in any fields, it submits straight away without any warning and empty fields.

Wondering why?

So this answer can get closed, and for better visibility of Nikhil's great comment, this isn't an issue with Bootstrap or Modals. It is simply a problem with the way the Safari browser deals with the required attribute in HTML5

From caniuse.com/#feat=form-validation:

Partial support in Safari refers to lack of notice when form with required fields is attempted to be submitted

Here's a Javascript polyfill for the required attribute in Safari:

<!-- language: lang-js -->

//Required attribute fallback
$('#formTemplate').submit(function() {
  if (!attributeSupported("required") || ($.browser.safari)) {
   //If required attribute is not supported or browser is Safari (Safari thinks that it has this attribute, but it does not work), then check all fields that has required attribute
   $("#formTemplate [required]").each(function(index) {
    if (!$(this).val()) {
     //If at least one required value is empty, then ask to fill all required fields.
     alert("Please fill all required fields.");
     return false;
    }
   });
  }
  return false; //This is a test form and I'm not going to submit it
});