javascript 取得圖片長寬

function getImgSize(imgSrc)
{
var newImg = new Image();
newImg.src = imgSrc;
var height = newImg.height;
var width = newImg.width;
alert ('The image size is '+width+'*'+height);
}
</script>

使用
onclick="getImgSize('images/testout_r1_c2.jpg')"