var is = new BrowserCheck(); // check browser.

function BrowserCheck() {
   var b = navigator.appName;
   var a = navigator.userAgent.toLowerCase();

   if (b=="Netscape") this.b = "ns";
   else if (b=="Microsoft Internet Explorer") this.b = "ie";
   else this.b = b;
   this.version = navigator.appVersion;
   this.v = parseInt(this.version);
   this.ns = (this.b=="ns" && this.v>=4);
   this.ns4 = (this.b=="ns" && this.v==4);
   this.ns5 = (this.b=="ns" && this.v==5);
   this.ie = (this.b=="ie" && this.v>=4);
   this.ie4 = (this.version.indexOf('MSIE 4')>0);
   this.ie5 = (this.version.indexOf('MSIE 5')>0);
   this.ie6 = (this.version.indexOf('MSIE 6')>0);
   this.min = (this.ns||this.ie);
   this.mac = a.indexOf('mac') >= 0;
}