var flag=false;
function DrawImage(ImgD){
var image=new Image();
image.src=ImgD.src;
if(image.width>0 && image.height>0){
	flag=true;
	if(image.width/image.height>= 200/300){
		if(image.width>200){ 
			ImgD.width=200;
			ImgD.height=(image.height*200)/image.width;
		}
		else{
			ImgD.width=image.width; 
			ImgD.height=image.height;
			}
			ImgD.alt="[点击查看大图]";
		}
	else{
		if(image.height>300){ 
			ImgD.height=300;
			ImgD.width=(image.width*300)/image.height; 
		}
		else{
			ImgD.width=image.width; 
			ImgD.height=image.height;
		}
			ImgD.alt="[点击查看大图]";
		}
	}
}