function imgWH(ImgD,w,h){
   var image=new Image();
   image.src=ImgD.src;
	if(image.width>0 && image.height>0){
	flag=true;
		if(image.width/image.height>= w/h){
				 if(image.width>w){  
				 ImgD.width=w;
				 ImgD.height=(image.height*w)/image.width;
				 }else{
				 ImgD.width=image.width;  
				 ImgD.height=image.height;
				 }
		}
		else{
				 if(image.height>h){  
				 ImgD.height=h;
				 ImgD.width=(image.width*h)/image.height;     
				 }else{
				 ImgD.width=image.width;  
				 ImgD.height=image.height;
				 }
		}
	}
}