Try out this code and include your unicode chinese/japanese in popup.htm
if(window.showModalDialog){
window.showModalDialog ('popup.htm','title_text','dialogHeight:150px;dialogWidth:200px;status:no;help:no;scroll:no;'); = "";
}
else{
alert("»¼¥æªí®æ");
}
Popup.htm
----------
<html>
<head><title>Title</title>
<meta http-equiv="Content-Type" content="text/html;charset:big5">
</head>
<body>
<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tr>
<td align="center"> </td>
</tr>
<tr>
<td align="center"> </td>
</tr>
<tr>
<td align="center">"»¼¥æªí®æ</td>
</tr>
</body>
</html>
If encoded character appears in the message box then, copy and paste chinese text directly inside <TD> instead of encoded text