function obtener_semestres(carrera, periodo){
	var slc_cant_carreras = document.getElementById('slc_carreras').length;
	var slc_cant_semestres = document.getElementById('slc_semestres').length;
	
	if(slc_cant_carreras == 5){
		document.getElementById('slc_carreras').remove(0);
	}
	
	if(carrera == 'ambiental') {
		if(periodo == 'impar')
			document.getElementById('slc_semestres').add(new Option("Noveno Semestre", "9"), null);
		else
			document.getElementById('slc_semestres').add(new Option("Decimo Semestre", "10"), null);	
	} else {
		
		if(slc_cant_semestres > 5){
			document.getElementById('slc_semestres').remove(slc_cant_semestres - 1);
		}
	}
		document.getElementById('slc_semestres').options["0"].selected = true;
	document.getElementById('slc_semestres').disabled = false;
}


function obtener_horario_clase(object, idioma, semestre){
	var carrera = document.getElementById('slc_carreras').value;
	obtener_articulo(object, idioma, 'academic', 'horario_clase_obtener', carrera, semestre);
}


function obtener_malla_curricular(idioma, carrera){
	if(document.getElementById('slc_carrera').length == 5)
		document.getElementById('slc_carrera').remove(0);
	obtener_articulo('malla_curricular', idioma, 'academic', 'malla_curricular_obtener', carrera);
}