Browser Detection trouble - I've written a browser detector for an assignment i'm doing in college, and i'm sure i've written it wrong: Code:

<script type="text/javascript">
if (/MSIE (\d+\.\d+) ;/ .test(navigator.UserAgent)) { //text for MSIE x.x;
 var ieversion=new Number(RegExp.$1) // capture x.x portion and store as a number
  if (ieversion>=8)
   alert("You're using IE8 or above")
  else if (ieversion>=7)
   alert("You're using IE7")
  else if (ieversion>=6)
   alert("You're using IE6")
  else if (ieversion>=5)
   alert("You're using IE5")
}
else
 alert("You are using a non-IE browser..")
</script>

<SCRIPT language="JavaScript">
<!--
var browserName=navigator.appName; 
if (browserName=="Netscape")
{ 
 alert("You're using Netscape as your browser!");
}
else 
{ 
 if (browserName=="Microsoft Internet Explorer")
 {
  alert("You are using Internet Explorer!")
 }
 else
  {
    alert("You are using a different browser :)");
   }
}
//-->
</SCRIPT>