ASP.NET MVC: C# Download file and save as dialog
<p>i've written this code which will generate an excel spreadsheet and save it to a specified location. I want to then display a "Save as" dialogue box by reading the file from the stored location and then asking then user where they want to store it.</p>

<pre><code>Excel.Application excelApp = null;
            Excel.Workbook wb = null;
            Excel.Worksheet ws = null;
            Excel.Range range = null;

excelApp = new Excel.Application();
            wb = excelApp.Workbooks.Add();
            ws = wb.Worksheets.get_Item(1) as Excel.Worksheet;

for(int i = 0; i&lt; 10;++i) {
    ws.Cells[i, 1] = i+
}

wb.SaveAs(@"C:\test.xls", Excel.XlFileFormat.xlWorkbookNormal);
wb.Close(true);
excelApp.Quit();
</code></pre>

<p>How to download in the following format?</p>

<pre><code>string str = "Hello, world"; 

byte[] bytes = System.Text.Encoding.UTF8.GetBytes(str); 

return File(bytes, "text/plain"); 
</code></pre>
