var ti = 0;
    
    
    function showHide(id)
     {
    	
    if (ti==0) {
	document.getElementById(id).style.visibility = "hidden";
	}
    	
        if (document.getElementById(id).style.visibility == "hidden")
          { 
              document.getElementById(id).style.visibility = "visible";
             ti = 1;
                           	

          } 
         else 
          { 
            document.getElementById(id).style.visibility = "hidden";
             ti = 1;
          } 
    }