function pan(k)
		   {
		      if (document.getElementById("dv_" + k).style.display == "none" )
			{
			document.getElementById("dv_" + k).style.display = "block";
			document.images["bb_" + k].src="images_index/str2.jpg";
			}
			else
			{
			document.getElementById("dv_" + k).style.display = "none";
			document.images["bb_" + k].src="images_index/str1.jpg";
			}						
		   }