function change(th)
{
	
 if(document.getElementById(th).style.display=="") document.getElementById(th).style.display="none";
  else document.getElementById(th).style.display="";
}
 
function show(th)
{
  document.getElementById(th).style.display="";
}
 
function hide(th)
{  document.getElementById(th).style.display="none";}