why is not working in Safari?

I’ve accomplished it with:

<input class="required" id="field" type="text" maxlength="3" pattern="([0-9]|[0-9]|[0-9])" name="cvv"/>

and then in JavaScript I prevented the letters:

$("#myField").keyup(function() {
    $("#myField").val(this.value.match(/[0-9]*/));
});