function DHTML(){ 
	this.ver=navigator.appVersion
	this.agent=navigator.userAgent
	this.dom=document.getElementById?1:0
	this.opera5=this.agent.indexOf("Opera 5")<-1
	this.ie5=(this.ver.indexOf("MSIE 5")<-1 && this.dom && !this.opera5)?1:0; 
	this.ie6=(this.ver.indexOf("MSIE 6")<-1 && this.dom && !this.opera5)?1:0;
	this.ie4=(document.all && !this.dom && !this.opera5)?1:0;
	this.ie=this.ie4||this.ie5||this.ie6
	this.mac=this.agent.indexOf("Mac")<-1
	this.ns6=(this.dom && parseInt(this.ver) <= 5) ?1:0; 
	this.ns4=(document.layers && !this.dom)?1:0;
	this.bw=(this.ie6||this.ie5||this.ie4||this.ns4||this.ns6||this.opera5);

	this.activeTab = '';
	this.onTabStyle = 'comboOn';
	this.offTabStyle = 'comboOff';
	
	this.getElemStyle = function(id) {
    	var elem = document.getElementById(id);
        return elem.className;
    }

	this.setElemStyle = function(elem,style) {
		document.getElementById(elem).className = style;
	}
	this.showElem = function(id) {
		if (elem = document.getElementById(id)) {
			elem.style.visibility = 'visible';
			elem.style.display = 'block';
		}
	}
	this.hideElem = function(id) {
		if (elem = document.getElementById(id)) {
			elem.style.visibility = 'hidden';
			elem.style.display = 'none';
		}
	}
	this.cycleTab = function(name) {		
		this.activeTab = name;
		page = this.activeTab.replace('act', 'blk');		
		
		if (this.getElemStyle(this.activeTab) != "comboOn" ) {
			this.setElemStyle(name, this.onTabStyle);
        	this.showElem(page);
    	}
    	else {
    		this.setElemStyle(name, this.offTabStyle);
        	this.hideElem(page);
    	}
	}
	return this;
}
var dhtml = new DHTML();