PrintDocument and PrintPreviewDialog

I am having issues getting my text to appear on a print preview document. I have not tried printing yet, since I cannot get the print preview to work correctly. I have looked through the MSDN references and found nothing related to setting the text, only setting the document. The document does exist and I have checked that multiple times. I think this is simply coming down to a very stupid error on my part and I cannot find out what it is.

Code:

        private void printPreviewToolStripButton_Click(object sender, EventArgs e)
        {
            if (open)
            {
                PrintDocument pd = new PrintDocument();
                PrintPreviewDialog ppd = new PrintPreviewDialog();
                string docName = "";
                string docPath = "";

                /* do other stuff not related to printing */

                docName = "pressureconversion.txt"; // the test file with valid text
                docPath = "./";

                pd.DocumentName = docPath + docName;
                //MessageBox.Show(docName); // test to see correct name
                //MessageBox.Show(docPath); // test to see correct path

                ppd.Document = pd;
                ppd.ShowDialog();
            }
            else
            {
                MessageBox.Show("There is nothing currently open!");
            }
        }

PrintDocument doesnt work the way you think it does. It is not used to print a document residing on the harddrive automatically, you need to connect a handler to the PrintPage event and call Print for anything to happen. Here is more documentation on how to use PrintDocument and an example of printing a txt file:

PrintDocument Class (System.Drawing.Printing)

This page contains an example of using a PrintDocument together with a PrintPreviewDialog:
PrintPreviewDialog Class (System.Windows.Forms)

Merging these 2 should give you a satisfactory result.