/**设置图片等比例缩放*/
function drawimage(ImgD,iwidth,iheight){    
    //参数(图片,允许的宽度,允许的高度)    
    var image=new Image();    
    image.src=ImgD.src;    
    if(image.width>0 && image.height>0){    
      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;    
          }    
      }    
    }    
}   



var flag=false;
function drawimage1(ImgD,ImgW,ImgH){
	var image=new Image();
	var iwidth =ImgW; //定义允许图片宽度，当宽度大于这个值时等比例缩小
	var iheight =ImgH; //定义允许图片高度，当高度大于这个值时等比例缩小
	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;
		}
	}
}