Email validation to implement in jQuery

$('form').on('submit',function() {
    var pmail = $('#pmail').val().trim()
    var smail = $('#smail').val().trim()

    //Check if there are values in either textbox
    //Otherwise show an alert and <code>return false;</code>

    //Check if the primary email and secondary email are valid emails, see solution 1.
    //Otherwise return false.

    //Check if primary email and secondary email are the same.
    if ( pmail === smail ) {
        alert('Please enter an address different from your primary email in the secondary email');
        return false;
    }
});

<form action="/action" id="form-id">
    <label for="pmail">Primary Email:
        <input type="email" name="pmail" id="pmail" placeholder="example@example.com">
    </label>
    <label for="smail">Secondary Email:
        <input type="email" name="smail" id="smail" placeholder="another@example.com">
    </label>
    <input type="submit" value="Submit Form">
</form>