var brw_v = navigator.appVersion.charAt(0);
var brw_n = navigator.appName.charAt(0);
var iIE4 = false;
var iNN4 = false;
if((brw_v >= 4)&&(brw_n == "M"))iIE4 = true;
if((brw_v >= 4)&&(brw_n == "N"))iNN4 = true;