function pic_with(obj,w_,h_)
{
w=w_;
h=h_;
 var srcImage = new Image();
 srcImage.src=obj.src;
 var srcW=srcImage.width;  
 var srcH=srcImage.height;
 if(srcW>srcH){
  if(srcW>w){
   obj.width=newW=w;
   obj.height=newH=(w/srcW)*srcH;
  }else{
   obj.width=newW=srcW;
   obj.height=newH=srcH;
  }
 }else{
  if(srcH>h){
   obj.height=newH=h;
   obj.width=newW=(h/srcH)*srcW;
  }else{
   obj.width=newW=srcW;
   obj.height=newH=srcH;
  }
 }
 if(newW>w){
  obj.width=w;
  obj.height=newH*(w/newW);
 }else if(newH>h){
  obj.height=h;
  obj.width=newW*(h/newH);
 }

}