Problem loading PHPExcel library with load

When I upload my file Prueba.php from the href it works without problem, when I load it from a load it does not work anymore.

But this way no longer, and I do so because I need to pass values before loading Excel.

Test.php

Function cargarPagina()

function cargaPagina(pagina) {

    var opcion = document.getElementById("opcion").value;

    $('body').css('background', '#fafafa');

    $('#' + opcion).toggle();
    $('#contenido').toggle();
    $('#opcion').val('contenido');

    $('#frmContenido').load(pagina);

}