private void compile_button_Click(object sender, EventArgs e)
        {
            CodeDomProvider provider = GetCurrentProvider();
            String          sourceFile;                                     // Build the source file name with the appropriate language extension.

            if (provider.FileExtension[0] == '.')
            {
                sourceFile = "TestGraph" + provider.FileExtension;
            }
            else
            {
                sourceFile = "TestGraph." + provider.FileExtension;
            }
            CompilerResults cr = CodeDomExample.CompileCode(provider,       // Compile the source file into an executable output file.
                                                            sourceFile,
                                                            "TestGraph.exe");

            if (cr.Errors.Count > 0)
            {
                textBox1.Text = "Errors encountered while building " +      // Display compilation errors.
                                sourceFile + " into " + cr.PathToAssembly + ": \r\n\n";
                foreach (CompilerError ce in cr.Errors)
                {
                    textBox1.AppendText(ce.ToString() + "\r\n");
                }
                run_button.Enabled = false;
            }
            else
            {
                textBox1.Text = "Source " + sourceFile + " built into " +
                                cr.PathToAssembly + " with no errors.";
                run_button.Enabled = true;
            }
        }
        private void generate_button_Click(object sender, EventArgs e)
        {
            CodeDomProvider provider = GetCurrentProvider();

            CodeDomExample.GenerateCode(provider, CodeDomExample.BuildHelloWorldGraph(HelloWordFrom.Text));

            String sourceFile;                                          // Build the source file name with the appropriate language extension.

            if (provider.FileExtension[0] == '.')
            {
                sourceFile = "TestGraph" + provider.FileExtension;
            }
            else
            {
                sourceFile = "TestGraph." + provider.FileExtension;
            }
            StreamReader sr = new StreamReader(sourceFile);             // Read in the generated source file and display the source text.

            textBox1.Text = sr.ReadToEnd();
            sr.Close();
        }