phpexcel not hiding column - php

Question

<?php
/** Include path **/
set_include_path(get_include_path() . PATH_SEPARATOR . '../../../Classes/');
/** PHPExcel_IOFactory */
include 'PHPExcel/IOFactory.php';
$inputFileType = 'Excel5';
$inputFileName = './source/marks.xls'; //using this in the meantime. Will replace later with an import feature
/** Create a new Reader of the type defined in $inputFileType **/
$objReader = PHPExcel_IOFactory::createReader($inputFileType);
/** Load $inputFileName to a PHPExcel Object **/
$objPHPExcel = $objReader->load($inputFileName);
echo '<hr />';
$objReader->setReadDataOnly(true);
$objPHPExcel = $objReader->load($inputFileName);
$objWorksheet = $objPHPExcel->getActiveSheet();
$objPHPExcel->getActiveSheet()->getColumnDimension('A')->setVisible(false);
echo '<table>' . "\n";
foreach ($objWorksheet->getRowIterator() as $row) {
echo '<tr>' . "\n";
$cellIterator = $row->getCellIterator();
$cellIterator->setIterateOnlyExistingCells(false); // This loops all cells,
foreach ($cellIterator as $cell) {
echo '<td>' . $cell->getValue() . '</td>' . "\n";
}
echo '</tr>' . "\n";
}
echo '</table>' . "\n";
?>
Please am working with this code for a school work. everything works well except the
$objPHPExcel->getActiveSheet()->getColumnDimension('D')->setVisible(false);
which is suppose to hide column D.
Function of the code is to read the individual marks from an excel file and display it in html view. eg.
My aim is to hide the Index no column from displaying in the html view. "removeColumn('A')" works but i am doing a search with the values in column A. So just want to hide that column.