browser_version= parseInt(navigator.appVersion);
browser_type= navigator.appName;

if (browser_type == "Microsoft Internet Explorer" && (browser_version >= 4)) { 
document.write("<IFRAME src='calendar1.asp'	 FRAMEBORDER=0 MARGINWIDTH=0 marginheight=0 width=100% height=250></IFRAME>");
}

else  { 
document.write("<a href='news.asp?textpage=new&mainpage=news'><img src='images/cal.gif'><br>Click for calendar</a>");
}