function nextsection (section) {
    if (section == "ivl1_index") {
		section = "ivl1_continents";
	} else if (section == "ivl2_index" ) {
	    section = "ivl2_mdaro";
	} else if (section == "ivl3_index") {
	    section = "ivl3_find";
	} else if (section == "ivl4_index") {
	    section = "ivl4_sorting";
	}
    window.location = '/schools/indusvalley/flash/' + section + '.shtml';
}