function Is(){
var agent = navigator.userAgent.toLowerCase();
this.major = parseInt(navigator.appVersion);
this.minor = parseFloat(navigator.appVersion);

this.ns = ((agent.indexOf('mozilla')!= -1) && ((agent.indexOf('spoofer')== -1) && (agent.indexOf('compatible')== -1)));
//this.ns4 = (this.ns && (this.major == 4));
this.ns6up = (this.ns && (this.major >= 5));

this.ie = (agent.indexOf("msie")!= -1);
this.ie4up = (this.ie && (this.major >= 4));
//this.ie5 = (this.ie && (this.major >= 4)&& (agent.indexOf("msie 5.")!=-1));
}