function big_img(obr,imgWidth,imgHeight) {
    var border = 24;
    var img = obr;
    var features;
    var w;
    var h;
	if(imgWidth+border<100) {winWidth=100;}else{winWidth=imgWidth+border;}
	if(imgHeight+border<100) {winHeight=100;}else{winHeight=imgHeight+border;}
    if (imgWidth+border > screen.width) {
        winWidth = screen.width-10;
        w = (screen.width - winWidth)/2;
        features = "scrollbars=yes";      
    } else {
        w = (screen.width - (imgWidth+border))/2;
    }
    if (imgHeight+border > screen.height) {
        winHeight = screen.height-60;
        h = 0;
        features = "scrollbars=yes";      
    } else {
        h = (screen.height - (imgHeight+border))/2 - 20;
    }    
    features = features+',toolbar=no,width='+winWidth+',height='+winHeight+',top='+h+',left='+w;
    theURL = './picture.php?img=fotogalerie/'+obr+'&maxwidth='+imgWidth+'&maxheight='+imgHeight;
    popup = window.open(theURL,'detail',features);
    popup.focus();  
}