function cambiar_pagina(opt)
{
	uri = new String(document.location);
	uri = uri.substring(0,uri.lastIndexOf("/")+1);
	actual_page = document.getElementById("combo_paginas").options[document.getElementById("combo_paginas").selectedIndex].value - 1; 
	actual_page += opt;
	location.href = uri + actual_page;
}
function cambiar_pagina_busqueda(opt)
{
	uri = new String(document.location);
	uri = uri.substring(0,uri.lastIndexOf("/")+1)+"buscar.php?page=";
	actual_page = document.getElementById("combo_paginas").options[document.getElementById("combo_paginas").selectedIndex].value - 1; 
	actual_page += opt;
	location.href = uri + actual_page;
}