代码：【复制】 
var flag=false;

function DrawImage(ImgD){

	var image=new Image();

	var iwidth = 650;

	var iheight = 500;

	image.src=ImgD.src;

	if(image.width>0 && image.height>0){

		flag=true;

		if(image.width/image.height>= iwidth/iheight){

			if(image.width>iwidth){ 

				ImgD.width=iwidth;

				ImgD.height=(image.height*iwidth)/image.width;

			}else{

				ImgD.width=image.width; 

				ImgD.height=image.height;

			}

		}else{

			if(image.height>iheight){ 

				ImgD.height=iheight;

				ImgD.width=(image.width*iheight)/image.height; 

			}else{

				ImgD.width=image.width; 

				ImgD.height=image.height;

			}

		}

	}

}