function displayWindow(theURL,winName,width,height,features) { 
    var window_width = width;
    var window_height = height;
    var newfeatures= features;
    var window_top = (screen.height-window_height)/2;
    var window_left = (screen.width-window_width)/2;
    newWindow=window.open('' + theURL + '','' + winName + '','width=' + window_width + ',height=' + window_height + ',top=' + window_top + ',left=' + window_left + ',features=' + newfeatures + '');
    newWindow.focus();}


function zobrazSkryj(idecko){
el=document.getElementById(idecko).style;
el.display=(el.display == 'block')?'none':'block';
}