function CheckBrowser(){

  this.win=(navigator.userAgent.indexOf("Win") >= 0)?1:0;

  this.ver=navigator.appVersion;

  this.dom=document.getElementById?1:0; 

  this.ie5=(this.ver.indexOf("MSIE")>-1 && this.dom)?1:0; 

  this.ie4=(document.all && !this.dom)?1:0;

  this.ns5=(this.dom && parseInt(this.ver) >= 5) ?1:0;

  this.ns4=(document.layers && !this.dom)?1:0;

  this.bw=(this.ie5 || this.ie4 || this.ns4 || this.ns5 || this.win);

  return this;

}