title: Save Excel Document in ASP.NET
body: <p><strong>Issue:</strong></p>
  
  <p>I am using the <code>Microsoft.Office.Interop.Excel</code> library in an ASP.NET application, and I have populated a Worksheet in a Workbook. I want the user to be prompted to Save the document to their machine, but I cannot find a way to do it (<code>myWorkbook.SaveAs(...)</code> doesn't work).</p>
  
  <p><strong>Question:</strong></p>
  
  <p>How can I get the Workbook saved to the user's machine? I've used <code>Response.Write(...)</code> to prompt the user to save a text-based file (CSV) before, but I cannot figure out how to do this for .xls files.</p>
  
  <p><strong>Bonus:</strong></p>
  
  <p>If this is not possible to do using the <code>Microsoft.Office.Interop.Excel</code> library, is there a free (Lesser GPL-ish) library I can use instead? </p>
  
  <p>I would assume that Microsoft would have a tool for this, but we all know what assuming does...</p>