Detecting whether Image Uploader is already installed

<script language="JavaScript">
<!--
//Image Uploader detection
if ((navigator.userAgent.indexOf('MSIE') != -1) && (navigator.userAgent.indexOf('Win') != -1)) {
    document.writeln('<script language="VBscript">');
    document.writeln('Function supportImageUploader()');        
    document.writeln('  If ScriptEngineMajorVersion >= 2 Then');    
    document.writeln('	  On Error Resume Next');
    document.writeln('	  supportImageUploader = "NotInstalled"');    
    document.writeln('    If IsObject(CreateObject("Aurigma.ImageUploader")) Then');
    document.writeln('      supportImageUploader = "Installed"');
    document.writeln('    End If');        
    document.writeln('	Else');
    document.writeln('    supportImageUploader = "Unsupported"');
    document.writeln('	End If');
    document.writeln('End Function');
    document.writeln('</scr' + 'ipt>');
}
else {
    document.writeln('<script language="JavaScript">');
    document.writeln('function supportImageUploader() {');
    document.writeln('	return "Unsupported";');
    document.writeln('}');
    document.writeln('</scr' + 'ipt>');
}

//Show either Image Uploader or alternative text
switch (supportImageUploader()){
	case "NotInstalled":
		alert("NotInstalled");
	break;
	case "Installed":
		alert("Installed");
	break;
	default: 
		alert("Unsupported");
}
//-->
</script>