function otevri_o(url, jmeno, w, h) {  
  leftVal = (screen.width - w) / 2;
  topVal = (screen.height - h) / 2;
popupWin = window.open(url, jmeno, 'resizable=1,top=' + topVal + ',left= ' + leftVal + ',menubar=0,scrollbars=yes,width=' + w + ',height=' + h);
}

function otevri_o_backurky() {  
  url = 'backurky.php';
  jmeno = 'aaaach';
  w = '592';
  h = '428';
  leftVal = (screen.width - 592) / 2;
  topVal = (screen.height - 428) / 2;
  popupWin = window.open(url, jmeno, 'resizable=1,top=' + topVal + ',left= ' + leftVal + ',menubar=0,scrollbars=yes,width=' + w + ',height=' + h);
}


function setWindow() {
    imgx = document.img.width;
    imgy = document.img.height;
    if(document.img.width > 984)  { imgx = 1024; } else { imgx += 40; }
    if(document.img.height > 723) { imgy = 768; }  else { imgy += 85; }
    window.resizeTo(imgx, imgy)
}

function setWindow_backurky() {
    imgx = document.img.width;
    imgy = document.img.height;
    imgx += 60;
    imgy += 80;
    window.resizeTo(imgx, imgy)
}