function NvScroll() {

this.version = "0.2";
this.name = "NvScroll";
this.item = new Array();
this.itemcount = 0;
this.currentspeed = 0;
this.scrollspeed = 50;
this.pausedelay = 1000;
this.pausemouseover = false;
this.stop = false;
this.type = 1;
this.height = 100;
this.width = 100;
this.stopHeight=0;
this.i=0;

this.add = function () {
	var text = arguments[0];

	this.item[this.itemcount] = text;
//	alert(this.item[this.itemcount]);
	this.itemcount ++;
};

this.start = function (layer_name) {
	if ( this.itemcount == 1 ) {
		this.add(this.item[0]);
	}
	if (layer_name != null)
	{
		document.getElementById(layer_name).innerHTML = this.str_ret();
	}
	else
	{
		this.display();
	}
	this.currentspeed = this.scrollspeed;
	if ( this.type == 1 || this.type == 2 ) {
		this.stop = true;
		setTimeout(this.name+'.scroll()',this.currentspeed);
		window.setTimeout(this.name+".stop = false", this.pausedelay);
	} else if ( this.type == 3 ) {
		this.stop = true;
		setTimeout(this.name+'.rolling()',this.currentspeed);
		window.setTimeout(this.name+".stop = false", this.pausedelay);
	}
};

this.display = function () {
	document.write('<div id="'+this.name+'" style="height:'+this.height+'; width:'+this.width+'; position:relative; overflow:hidden; " OnMouseOver="'+this.name+'.onmouseover(); " OnMouseOut="'+this.name+'.onmouseout(); ">');
	for(var i = 0; i < this.itemcount; i++) {
		if ( this.type == 1 ) {
			document.write('<div id="'+this.name+'item'+i+'"style="left:0px; width:'+this.width+'; position:absolute; top:'+(this.height*i)+'px; ">');
			document.write(this.item[i]);
			document.write('</div>');
		} else if ( this.type == 2 || this.type == 3 ) {
			document.write('<div id="'+this.name+'item'+i+'"style="left:'+(this.width*i)+'px; width:'+this.width+'; position:absolute; top:0px; ">');
			document.write(this.item[i]);
			document.write('</div>');
		}
	}
	document.write('</div>');
};


this.rolling = function () {
	if ( this.stop == false  ) {
		this.next();
	}
	window.setTimeout(this.name+".rolling()",this.scrollspeed);
}

this.onmouseover = function () {
	if ( this.pausemouseover ) {
		this.stop = true;
	}
};

this.onmouseout = function () {
	if ( this.pausemouseover ) {
		this.stop = false;
	}
};

this.next = function() {

	for (i = 0; i < this.itemcount; i++) {
		obj = document.getElementById(this.name+'item'+i).style;
		if ( parseInt(obj.left) < 1 ) {
			width = this.width + parseInt(obj.left);
			break;
		}
	}
	for (i = 0; i < this.itemcount; i++) {
		obj = document.getElementById(this.name+'item'+i).style;
		if ( parseInt(obj.left) < 1 ) {
			obj.left = this.width * (this.itemcount-1);
		} else {
			obj.left = parseInt(obj.left) - width;
		}
	}

}

this.prev = function() {

	for (i = 0; i < this.itemcount; i++) {
		obj = document.getElementById(this.name+'item'+i).style;
		if ( parseInt(obj.left) < 1 ) {
			width = parseInt(obj.left) * (-1);
			break;
		}
	}
	if ( width == 0 ) {
		total_width = this.width * (this.itemcount-1);
		for (i = 0; i < this.itemcount; i++) {
			obj = document.getElementById(this.name+'item'+i).style;
			if ( parseInt(obj.left) + 1 > total_width ) {
				obj.left = 0;
			} else {
				obj.left = parseInt(obj.left) + this.width;
			}
		}
	} else {
		for (i = 0; i < this.itemcount; i++) {
			obj = document.getElementById(this.name+'item'+i).style;
			if ( parseInt(obj.left) < 1 ) {
				obj.left = 0;
			} else {
				obj.left = parseInt(obj.left) + width;
			}
		}
	}
}

this.unext = function () {
	this.onmouseover();
	this.next();
	window.setTimeout(this.name+".onmouseout()",this.pausedelay);
}

this.uprev = function () {
	this.onmouseover();
	this.prev();
	window.setTimeout(this.name+".onmouseout()",this.pausedelay);
}

}