Slow JavaScript

I've got an HTML form where the maximum field value is set to 1 character. As a result, the JavaScript needs to be super-fast. But upon testing, it appears I am too fast for the script, so it misses characters unless I type slowly.

<script type="text/javascript">
   function formfocus() {
      document.getElementById('element').focus();
   }
   window.onload = formfocus;

function moveOnMax(field,nextFieldID){
开发者_如何学编程  if(field.value.length >= field.maxLength){
    document.getElementById(nextFieldID).focus();
  }
}
</script>

<input class="text" type="text" name="1" id="element" maxlength="1" onkeyup="moveOnMax(this,'2')"><input class="text" id="2" onkeyup="moveOnMax(this,'3')" type="text" name="2" maxlength="1">

Anyone know a way to speed this up, or am I stuck with having to instruct visitors to type slowly?

As you have mentioned maxlength of all fields are 1 character, then why to check length of the values of each field just in onkeyup event handler of every field make the focus to next field.

<script type="text/javascript">
   function formfocus() {
      document.getElementById('element').focus();
   }
   window.onload = formfocus;

function moveOnMax(nextFieldID){
    document.getElementById(nextFieldID).focus();
}
</script>

<input class="text" type="text" name="1" id="element" maxlength="1" onkeyup="moveOnMax('2')">
<input class="text" id="2" onkeyup="moveOnMax('3')" type="text" name="2" maxlength="1">
<input class="text" id="3" onkeyup="moveOnMax('4')" type="text" name="2" maxlength="1">