// convert all characters to lowercase to simplify testing
    var agt=navigator.userAgent.toLowerCase();

// browser version
// Note: On IE5, these return 4, so use is_ie5up to detect IE5.
    var bver = parseInt(navigator.appVersion);
    var is_nav  = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('compatible') == -1));
    var is_nav3 = (is_nav && (bver == 3));
    var is_nav4 = (is_nav && (bver == 4));
    var is_nav4up = (is_nav && (bver >= 4));
//    var is_navonly = (is_nav && ((agt.indexOf(";nav") != -1) || (agt.indexOf("; nav") != -1)) );
//    var is_nav6 = (is_nav && (bver == 5));
    var is_nav6up = (is_nav && (bver >= 5));
//    var is_gecko = (agt.indexOf('gecko') != -1);
    var is_ie     = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
    var is_ie3    = (is_ie && (bver < 4));
//    var is_ie4    = (is_ie && (bver == 4) && (agt.indexOf("msie 4")!=-1) );
    var is_ie4up  = (is_ie && (bver >= 4));
//    var is_ie5    = (is_ie && (bver == 4) && (agt.indexOf("msie 5.0")!=-1) );
//    var is_ie5_5  = (is_ie && (bver == 4) && (agt.indexOf("msie 5.5") !=-1));
//    var is_ie5up  = (is_ie && !is_ie3 && !is_ie4);
//    var is_ie5_5up =(is_ie && !is_ie3 && !is_ie4 && !is_ie5);
//    var is_ie6    = (is_ie && (bver == 4) && (agt.indexOf("msie 6.")!=-1) );
//    var is_ie6up  = (is_ie && !is_ie3 && !is_ie4 && !is_ie5 && !is_ie5_5);


  if (is_nav6up) {
  	document.write('<link rel="stylesheet" href="http://www.rom.gov.sg/rom/style/menu_style_ie.css" type="text/css">');
  }
  
  else if (is_nav4) {
  	document.write('<link rel="stylesheet" href="http://www.rom.gov.sg/rom/style/menu_style_nav4.css" type="text/css">');
  }
  
  else if (is_ie4up) {
  	document.write('<link rel="stylesheet" href="http://www.rom.gov.sg/rom/style/menu_style_ie.css" type="text/css">');
  }