// JavaScript Document
var flag=false; 
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){ 
    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; 
        } 
    } 
}