boxen = new Array("box_1997", "box_1999", "box_2002", "box_2005", "box_2010");
 
  function activateBlock(box_id)
 {
	 for (var i = 0; i < boxen.length; ++i){
document.getElementById(boxen[i]).style.display='none';
}
	  

	 	 if(document.getElementById(box_id).style.display=='block') {
		 document.getElementById(box_id).style.display='none';
	 } else
{	 document.getElementById(box_id).style.display='block'};
 }
 
   function deactivateBlock(box_id)
   {
	   document.getElementById(box_id).style.display='none';
   }