alto = screen.height/1.5;
ancho = screen.width/1.2;
arr = screen.height/2 - alto/2;
izq = screen.width/2 - ancho/2;

function vercompra(){
	    newopen = window.open ("tienda/cesta.php?codigo=ver", "cestacompra", "height="+alto+",width="+ancho+",top="+arr+",left="+izq+", location=no, scrollbars");
		newopen.focus();
}

function comprar(referencia,nombre,precio){
	    newopen = window.open ("tienda/cesta.php?codigo="+referencia+"&texto="+nombre+"&precio="+precio, "cestacompra", "height="+alto+",width="+ancho+",top="+arr+",left="+izq+", location=no, scrollbars");
		newopen.focus();
}