function viewInstr(url) {
  instructions=url.substring(0,url.indexOf("."));
  moveToX=Math.max(0,(screen.width-550)/2);
  moveToY=Math.max(0,(screen.height-300)/2);
  url='instructions/' + url;
  options ='toolbar=no,';
  options+='location=no,';
  options+='directories=no,';
  options+='status=no,';
  options+='scrollbars=yes,';
  options+='resizable=yes,';
  options+='copyhistory=no,';
  options+='screenX='+moveToX+',';
  options+='screenY='+moveToY+',';
  options+='left='+moveToX+',';
  options+='top='+moveToY+',';
  options+='width=550,';
  options+='height=300';
  popup=window.open(url,instructions,options);
  popup.moveTo(moveToX,moveToY);
}