Check for "letter-only" INPUT - Real's Javascript How-to

To check for regular ASCII (no accent)

<script>
function validate(strValue) {
  var objRegExp  = /^[a-z]+$/;
  return objRegExp.test(strValue);
}
</script>

A more friendly approach is to accept accented letters too!

<script>
function validate(strValue) {
  var objRegExp  = /^[a-z\u00C0-\u00ff]+$/;
  return objRegExp.test(strValue);
}

Try it here : If you want to accept a space then

  var objRegExp  = /^[a-z\u00C0-\u00ff\s]+$/;