/*按比例生成缩略图*/
function DrawImage(ImgD,W,H){ 
  var flag=false; 
   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;
     }
     }
    }
}
/*按透明度*/
function high(which2){
theobject=which2
highlighting=setInterval("highlightit(theobject)",20)
}
function low(which2){
clearInterval(highlighting)
which2.filters.alpha.opacity=75
}
function highlightit(cur2){
if (cur2.filters.alpha.opacity<100)
cur2.filters.alpha.opacity+=5
else if (window.highlighting)
clearInterval(highlighting)
}