function BrowserCheck() {
	var b = navigator.appName;
	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.ie = (this.b=="ie" && this.v>=4);
	this.min = (this.ns||this.ie);
};

is = new BrowserCheck();