function HorizontalButtonMenu() {
	var instance = this;
	
	this.btncount = 0;
	
	this.addButton = addButton;
	
	//public
	function addButton(label, doc, bmargin) {
		if (document.getElementById) {
			var btnid = 'btn' + instance.btncount;
			document.writeln('<div id="btn" style="margin-bottom:'+bmargin+'px;"><a href="'+doc+'" target="contentframe" id="'+btnid+'">'+label+'<\/a><\/div>');
			manageEvents(btnid);
			var activebtnid = 'btn0';
			document.getElementById(activebtnid).active = true;
			document.getElementById(activebtnid).className = 'btn_click';
			
			instance.btncount++;
		}
	}
	//private
	function manageEvents(id) {
		var currentbutton = document.getElementById(id);
		currentbutton.onfocus = function() {if (this.blur) this.blur();}
		currentbutton.onmouseover = setOver;
		currentbutton.onmouseout = setOut;
		currentbutton.onclick = setActive;
	}
	function setOver() {
		if (!this.active) this.className = 'btn_over';
	}
	function setOut() {
		if (!this.active) this.className = 'btn_out';
	}
	function setActive() {
		for (var i = 0; i < instance.btncount; i++) {
			var cb = 'btn' + i;
			document.getElementById(cb).active = false;
			document.getElementById(cb).className = 'btn_out';
		}
		this.active = true;
		this.className = 'btn_click';
	}
}