title: PHPExcel removes Data Validation Option of Excel sheet after editing existing Excel Sheet
body: <p>I am using <code>PHPExcel</code> for editing existing excel sheets.</p>
  
  <p>I had already set up a Data Validation method in my excel sheet as below.
  <img src="https://i.stack.imgur.com/jWq9c.png" alt="enter image description here"></p>
  
  <p>When i edit this excel using <code>PHPExcel</code>, this Excel Specific Data Validation vanishes.</p>
  
  <p>Can anyone help me to overcome this issue. I need to edit the excel without changing its functionality.</p>
  
  <p><strong>My PHP code:</strong></p>
  
  <pre><code> //load existing template..
  $objPHPExcel = PHPExcel_IOFactory::load('www/PHPExcelReader/Excel_Uploads/sample.xls');
  
  // Set document properties
  $objPHPExcel-&gt;getProperties()-&gt;setCreator("Logic Item")
                               -&gt;setLastModifiedBy("Logic")
                               -&gt;setTitle("List");
  $objPHPExcel-&gt;setActiveSheetIndex(0)-&gt;setCellValue('AZ1', $combination);
  
  // Set active sheet index to the first sheet, so Excel opens this as the first sheet
  $objPHPExcel-&gt;setActiveSheetIndex(0);
  $objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
  $file_name='sample.xls';
  $objWriter-&gt;save($file_name);
  echo "Excel is ready to download now...";
  </code></pre>