jQuery(window).load(function () {  
jQuery("#div_id img").each(function () {  
DrawImage(this, 500, 1000);
});  
});  
function DrawImage(ImgD, FitWidth, FitHeight) {  
var image = new Image();  
image.src = ImgD.src;  
if (image.width > 0 && image.height > 0) {  
if (image.width / image.height >= FitWidth / FitHeight) {  
if (image.width > FitWidth) {  
ImgD.width = FitWidth;  
ImgD.height = (image.height * FitWidth) / image.width;  
} else {  
ImgD.width = image.width;  
ImgD.height = image.height;  
}  
} else {  
if (image.height > FitHeight) {  
ImgD.height = FitHeight;  
ImgD.width = (image.width * FitHeight) / image.height;  
} else {  
ImgD.width = image.width;  
ImgD.height = image.height;  
}  
}  
}  
}