// Cambia la dimensione di un'immagine
function changeSize(imgSrc, iSizeX, iSizeY)
{
    var newImg = new Image();
    newImg.src = imgSrc.src;
    var height = newImg.height;
    var width = newImg.width;
    // Calcolo l'aspect ratio
    var ar = width / height;
    // Se w>h cambio width
    if (width>=height){
        imgSrc.width = iSizeX;
        imgSrc.height = iSizeY / ar;
    }
    if (height>width){
        imgSrc.height = iSizeY;
        imgSrc.width = iSizeX * ar;
    }
}