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[elsaiya]

Bueno amigo este es la estructura de la tabla alumnos

CREATE TABLE `alumnos` (
`Id_alumno` int(11) NOT NULL AUTO_INCREMENT,
`Ced_alumno` varchar(12) COLLATE utf8_spanish_ci NOT NULL,
`Nom_alumno` varchar(25) COLLATE utf8_spanish_ci DEFAULT NULL,
`Ape_alumno` varchar(25) COLLATE utf8_spanish_ci DEFAULT NULL,
`Direc_alumno` varchar(70) COLLATE utf8_spanish_ci DEFAULT NULL,
`Sexo` varchar(10) COLLATE utf8_spanish_ci DEFAULT NULL,
`Nacional` varchar(11) COLLATE utf8_spanish_ci DEFAULT NULL,
`Telf` varchar(20) COLLATE utf8_spanish_ci DEFAULT NULL,
`Fech_nac` date DEFAULT NULL,
`Lug_nac` varchar(25) COLLATE utf8_spanish_ci DEFAULT NULL,
`Grado` varchar(10) COLLATE utf8_spanish_ci NOT NULL,
`Mat_pend` varchar(50) COLLATE utf8_spanish_ci NOT NULL,
`Repite` varchar(2) COLLATE utf8_spanish_ci NOT NULL,
`Inst_proc` varchar(30) COLLATE utf8_spanish_ci NOT NULL,
`Tiempo` varchar(15) COLLATE utf8_spanish_ci DEFAULT NULL,
`Fech_inscrip` date NOT NULL,
PRIMARY KEY (`Id_alumno`)
) ENGINE=InnoDB AUTO_INCREMENT=77 DEFAULT CHARSET=utf8 COLLATE=utf8_spanish_ci;

y el formulario es este