var clicked = 0;
function mostrar(element,a,b,c,d)
	{
	if (d == null) 
		{ d = 0.5 ; } 
	if (clicked > 0) 
		{new Effect.Move( element, { x: a, y: b, mode: 'absolute', duration: d }); clicked = 0 ;}
		else 
		{new Effect.Move( element, { x: a, y: c, mode: 'absolute', duration: d }); clicked = 1 ;}
	}