function popup(fname,pic_x,pic_y){
	if(((pic_x>screen.width) && (pic_y>screen.height)) || (!(pic_x>0)) || (!(pic_y>0))){
	   pic_x=screen.width;pic_y=screen.height;
	}
	x=pic_x;y=pic_y;min_x=50;min_y=50;x=(x> min_x)?x+1:min_x;y=(y> min_y)?y+1:min_y;ytop=screen.height/2-y/2;xleft=screen.width/2-x/2;
	window.open(fname,"","toolbar=no,scrollbars=auto,width="+x+",height="+y+", top="+ytop+", left="+xleft);
}
var prediv=0;
function showdiv(layername){
  if(prediv>0) document.getElementById('fb_'+prediv).style.display='none';
  if(prediv!=layername){
      document.getElementById('fb_'+layername).style.display='block';
      prediv=layername; 
  }else prediv=0;
}
function hidediv (){
    if(prediv>0) document.getElementById(prediv).style.display='none';
    prediv=0; 
}