Comprobar input w/ regex

by Luis Martin

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" id="prueba">

<p id="resultado"></p>

JavaScript

function comprobar() {
  var elem = document.getElementById("prueba");
  var pattern = new RegExp(/^[a-z\u00E0-\u00FC]+(\s[a-z\u00E0-\u00FC]+)+$/i);


  if (pattern.test(elem.value.trim()) || elem.value.trim() == "") {

    elem.style.borderBottomColor = elem.style.borderTopColor;

    return true;
  } else {

    elem.style.borderBottomColor = "red"

    return false;

  }


}

$('input').bind('input propertychange', function() {
  comprobar();
});