// identifica o browser
var AgntUsr=navigator.userAgent.toLowerCase();
var DomYes=document.getElementById?1:0;
var NavYes=AgntUsr.indexOf('mozilla')!=-1&&AgntUsr.indexOf('compatible')==-1?1:0;
var Nav4=NavYes&&!DomYes&&document.layers?1:0;
//
var M_Hide=Nav4?'hide':'hidden';
var M_Show=Nav4?'show':'visible';

function swapImage(imgName, imgSrc) {
    imgName.src = imgSrc;
}

function hideShowInfo(show) {
    if (show) info.style.visibility = M_Show;
    else info.style.visibility = M_Hide;
}

function openPopup(_url,_winName,_width,_height,_scroll) {
    // posiciona a popup no meio da tela
    _y = (screen.height - _height) / 2;
    _x = (screen.width - _width) / 2;
    //alert('screen: ' + screen.width + 'x' + screen.height + '\npopup: ' + _x + 'x' + _y);
    win = window.open(_url,_winName,'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=' + _scroll + ',resizable=no,copyhistory=no,top=' + _y + ',left=' + _x + ',screenY=' + _y + ',screenX=' + _x + ',width=' + _width + ',height=' + _height);
    win.focus();
}