<HTML> <HEAD> <TITLE>Script </TITLE> <SCRIPT LANGUAGE="JavaScript"> <!-- function hanCheck(x) { for(i=0;i<x.user_id.value.length;i++) { var a=x.user_id.value.charCodeAt(i); if (a > 128) { alert('ÇÑ±Û ÀÔ·Â ±ÝÁö'); x.user_id.value=""; x.user_id.focus(); return; } } alert("ok"); } //--> </SCRIPT> </HEAD> <BODY> <form> User_id <input type=text name="user_id"> <input type=button onClick="hanCheck(this.form)" value="Check"> </form> </BODY> </HTML>