function toggle_visibility(id) 
	{
       var e = document.getElementById(id);
       if(e.style.display == 'block')
          e.style.display = 'none';
       else
          e.style.display = 'block';
    }

function btncancel() 
	{
	if (document.getElementById("aa"))//to clear the content of iframe if it is there
		{
			var iframe = document.getElementById('aa');
			iframe.parentNode.removeChild(iframe);
		}
	}