如何让html输入域中只填写英文，不能填写中文

<script language=javascript>

var keylastuplength=0;

function onlyEng() //禁止用户输入中文或中文符号

{

var thisval=document.getElementById('catalogCode').value;

var cArr = thisval.match(/[^\x00-\xff]/ig);

var lengthstr =thisval.length + (cArr == null ? 0 : cArr.length);

if(thisval.length!=lengthstr){

document.getElementById('catalogCode').value=document.getElementById('catalogCode').value.substring(0,keylastuplength);

}else{

keylastuplength = thisval.length;

}

}

</script>

<s:textfield cssClass="form-control"

onkeyup="onlyEng();"

id="catalogCode" required="required"

placeholder="栏目标识号 如（ceshilanmu）"

name="catalogInfo.cataCode">

</s:textfield>