浏览器验证

function checkBrowser()
{
this.ver=navigator.appVersion
this.dom=document.getElementById?1:0
this.ie6=(this.ver.indexOf("MSIE 6")>-1 && this.dom)?1:0;
this.ie5=(this.ver.indexOf("MSIE 5")>-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.mac=(this.ver.indexOf('Mac') > -1) ?1:0;
this.ope=(navigator.userAgent.indexOf('Opera')>-1);
this.ie=(this.ie6 || this.ie5 || this.ie4)
this.ns=(this.ns4 || this.ns5)
this.bw=(this.ie6 || this.ie5 || this.ie4 || this.ns5 || this.ns4 || this.mac || this.ope)
this.nbw=(!this.bw)
return this;
}