var flag=false;
function DrawImage(ImgD,kd,gd){
	var image=new Image();
	var iwidth = kd;  //定义允许图片宽度
	var iheight = gd;  //定义允许图片高度
	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;
		}
		ImgD.alt=image.width+"×"+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;
		}
		ImgD.alt=image.width+"×"+image.height;
		}
	}
}