function Is () 
{   // convert all characters to lowercase to simplify testing 
    var agt=navigator.userAgent.toLowerCase(); 
	
	// Browsers adhering to the w3c DOM
	this.DOM = (document.createRange) ? true : false;
    
    // *** BROWSER VERSION *** 
    // Note: On IE5, these return 4, so use is.ie5up to detect IE5. 
    this.major = parseInt(navigator.appVersion); 
    this.minor = parseFloat(navigator.appVersion); 
	
    this.nav  = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('spoofer')==-1) 
                && (agt.indexOf('compatible') == -1) && (agt.indexOf('opera')==-1) 
                && (agt.indexOf('webtv')==-1)); 
    this.nav2 = (this.nav && (this.major == 2)); 
    this.nav3 = (this.nav && (this.major == 3)); 
    this.nav4 = (this.nav && (this.major == 4)); 
    this.nav4up = (this.nav && (this.major >= 4)); 
    this.navonly      = (this.nav && ((agt.indexOf(";nav") != -1) || 
                          (agt.indexOf("; nav") != -1)) ); 
    this.nav5 = (this.nav && (this.major == 5)); 
    this.nav5up = (this.nav && (this.major >= 5)); 
	this.nav405lss = (this.nav && (this.minor <= 4.05));
	this.nav6 = (this.nav && (this.major == 5));
    this.nav6up = (this.nav && (this.major >= 5));
    this.gecko = (agt.indexOf('gecko') != -1);
	//alert(this.nav6up);

    this.ie   = (agt.indexOf("msie") != -1); 
    this.ie3  = (this.ie && (this.major < 4)); 
    this.ie4  = (this.ie && (this.major == 4) && (agt.indexOf("msie 5.0")==-1) ); 
	this.ie401 = (this.ie && (agt.indexOf("msie 4.01") != -1));
    this.ie4up  = (this.ie  && (this.major >= 4)); 
    this.ie5  = (this.ie && (this.major == 4) && (agt.indexOf("msie 5.0")!=-1) ); 
	this.ie5_5  = (this.ie && (this.major == 4) && (agt.indexOf("msie 5.5") !=-1));
	this.ie5up  = (this.ie  && !this.ie3 && !this.ie4); 
	this.ie55up =(this.ie && !this.ie3 && !this.ie4 && !this.ie5);
    this.ie6    = (this.ie && (this.major == 4) && (agt.indexOf("msie 6.")!=-1) );
    this.ie6up  = (this.ie && !this.ie3 && !this.ie4 && !this.ie5 && !this.ie5_5);


    this.aol   = (agt.indexOf("aol") != -1); 
    this.aol3  = (this.aol && this.ie3); 
    this.aol4  = (this.aol && this.ie4); 

    // *** JAVASCRIPT VERSION CHECK *** 
    if (this.nav2 || this.ie3) this.js = 1.0 
    else if (this.nav3 || this.opera) this.js = 1.1 
    else if ((this.nav4 && (this.minor <= 4.05)) || this.ie4) this.js = 1.2 
    else if ((this.nav4 && (this.minor > 4.05)) || this.ie5) this.js = 1.3 
    else if (this.nav5) this.js = 1.4 
    else if (this.nav6 || this.gecko) this.js = 1.5
    // NOTE: In the future, update this code when newer versions of JS
    // are released. For now, we try to provide some upward compatibility
    // so that future versions of Nav and IE will show they are at
    // *least* JS 1.x capable. Always check for JS version compatibility
    // with > or >=.
    else if (this.nav6up) this.js = 1.5;
    else if (this.nav && (this.major > 5)) this.js = 1.4 
    else if (this.ie && (this.major > 5)) this.js = 1.3 
    // HACK: no idea for other browsers; always check for JS version with > or >= 
    else this.js = 0.0; 

    this.mac    = (agt.indexOf("mac")!=-1); 
} 

var is; 
var isIE3Mac = false; 
// this section is designed specifically for IE3 for the Mac 

if ((navigator.appVersion.indexOf("Mac")!=-1) && (navigator.userAgent.indexOf("MSIE")!=-1) && (parseInt(navigator.appVersion)==3)) 
       isIE3Mac = true; 
else   is = new Is();