from here:  http://www.javascriptfreecode.com/2.htm


1- Make your website as user's Homepage

<!-- this script got from www.javascriptfreecode.com coded by: Krishna Eydatoula-->

<A class=chlnk

            style="CURSOR: hand; font-decoration: underline"

            onclick="this.style.behavior='url(#default#homepage)';this.setHomePage('http://www.javascriptfreecode.com');"

            href="\">set as your home page</A><br><font face="Tahoma">

           

           

<font face="Tahoma"><a target="_blank" href="http://www.javascriptfreecode.com/"><span style="font-size: 8pt; text-decoration: none">JavaScript Free Code</span></a></font>



2-  A message box when page opens
<!-- this script got from www.javascriptfreecode.com coded by: Krishna Eydatoula-->
<html>
<head>
<script language="javascript" type="text/javascript">
alert("Welcome to my site")
</script>
</head>
</html>      
<font face="Tahoma"><a target="_blank" href="http://www.javascriptfreecode.com/"><span style="font-size: 8pt; text-decoration: none">JavaScript Free Code</span></a></font>