var usra = navigator.userAgent;
var appna = navigator.appName;
var osMac = (usra.indexOf("Mac") != -1)?true:false;
var osWin = (usra.indexOf("Win") != -1)?true:false;
var NSbr = (appna.indexOf("Netscape") != -1)?true:false;
var NS6 = ((usra.indexOf("Gecko") != -1)&&(usra.indexOf("Netscape") != -1))?true:false;
var MSbr = (usra.indexOf("MSIE") != -1)?true:false;

var domm;
// get layer object
function getlayobj(laynam){
    if(document.getElementById && document.getElementById(laynam)){
    	domm = 1;// MSIE 5, NN 6
		return document.getElementById(laynam).style;
    }else if(document.all && document.all(laynam)){
    	domm = 2;// MSIE 4
		return document.all(laynam).style;
    }else if(document.layers && document.layers[laynam]){
    	domm = 3;// NN 4
		return document.layers[laynam];
    }else{
    	domm = 0;
		return false;
    }
}
function mvlay(laynam, vv){
    var lyobj = getlayobj(laynam);
    if(domm==1){lyobj.top = vv;}
    else if(domm==2){lyobj.pixelTop= vv;}
    else if(domm==3){lyobj.moveTo(0,vv);}
}
function mvbylay(layernam, vv){ // relative
	var lyobj = getlayobj(layernam);
	if(domm==1){
		var vvv;
		if(NS6){vvv=vv*2;}else{vvv=vv;}
		lyobj.top = parseInt(lyobj.top)+vvv;
	}
	else if(domm==2){lyobj.pixelTop +=vv;}
	else if(domm==3){lyobj.moveBy(0,vv);}
}

var dis;
if(osMac && MSbr){dis=7;}else{dis=2}
var scrlmax=2373, scrlmini=0;
var timerval=10;
var defctop=0; var defcr=80; var defcl=0;
var defcbtm, pcbtm;

var scrlset;
function doscrl(nu,sp){
	var lyobj = getlayobj('bar');
	var ptop;
	if(domm==1){ptop=parseInt(lyobj.top);}else if(domm==2){ptop=lyobj.pixelTop;}else if(domm==3){ptop=lyobj.top;}
	if(sp){var spe=dis+8}else{var spe=dis}
	if(nu){
		if(ptop >= ((scrlmax*-1)+200)){
			mvbylay('bar', spe*-1);
			scrlset = setTimeout('doscrl(1,'+sp+')',timerval);
		}else{
			clearTimeout(scrlset);
		}
	}else{
		if(ptop >= scrlmini){
			mvlay('bar', scrlmini);
			clearTimeout(scrlset);
		}else{
			mvbylay('bar', spe);
			scrlset = setTimeout('doscrl(0,'+sp+')',timerval);
		}
	}
}
function clearscrl(){
	clearTimeout(scrlset);
}


function chimg(arg,arv){
	eval("document." + arg + ".src = '../image/button_" + arv + ".gif'");
}