js 通过src 获取图片大小

checkImgWidHei("<%=basePath%>"+response);

传一个src

function checkImgWidHei(imgSrc){
var img = new Image();
img.onload = function(){
img.onload = null;
if(img.width!=869){
alert("图片宽度不等于标准尺寸869px");
document.getElementById("credetPhotoImage").src ="<%=basePath%>source/image/big.png";
}
else if(img.height!=489){
alert("图片高度不等于标准尺寸489px");
document.getElementById("credetPhotoImage").src ="<%=basePath%>source/image/big.png";
}
};
img.src = imgSrc;
}