<input id=aa><input type=button onclick="aaa()">
<script>
function aaa() {
var s = true;
for(var i =0;i<document.all.aa.value.length;i++)
{
var s1 = document.all.aa.value.charCodeAt(i);if(s1>=255)
{s = false ;
break;}
}
if(!s )
alert("有汉字");
}
</script>
<script>
function aaa() {
var s = true;
for(var i =0;i<document.all.aa.value.length;i++)
{
var s1 = document.all.aa.value.charCodeAt(i);if(s1>=255)
{s = false ;
break;}
}
if(!s )
alert("有汉字");
}
</script>
function checkChinese(){
var re = /[\u4E00-\u9FA0]+/;
if (re.test(form1.aa.value))
{
alert("不允许输入中文!");
return false;
}
}
</script>
</HEAD><BODY>
<FORM METHOD=POST ACTION="" name=form1 onsubmit="return checkChinese();">
<INPUT TYPE="text" NAME="aa"><br>
<INPUT TYPE="submit" NAME="submit" value="检查中文">
</FORM>
<hr>
或者:<input style="ime-mode:disabled" onpaste="return false">