read process output and insert input

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Hi,

I started a thread regarding this issue, but now i'm facing new problem, so
i'm starting a new thread, hope it's ok...

anyway, using my c# windows application, i'm excuting and exe file (which is
written in c++), this exe excute some batch files, and those batch file
sometimes wait for user's input.
i want to diplay the output of this exe on win32 form (textbox or something)
and ask the user for input when i need it. the problem is, that i read each
line using ReadLine() function, but when it gets to the stage where the
script needs an input, the process is stuck since readline didn't find a new
line or something like that.
i'm looking for a way to read the output till the point that the user should
insert input, and then insert the input. I saw some c++ program that did that
using pipes and other stuff i couldn't understand.
this is my code:

Process p = new Process();
StreamWriter sw;
StreamReader sr;
StreamReader err;
ProcessStartInfo psI = new ProcessStartInfo();
psI.FileName = @"D:\gidi.exe";
psI.Arguments = "hello gidi";
psI.UseShellExecute = false;
psI.RedirectStandardInput = true;
psI.RedirectStandardOutput = true;
psI.RedirectStandardError = true;
psI.CreateNoWindow = true;
p.StartInfo = psI;
p.Start();
sw = p.StandardInput;
sr = p.StandardOutput;
err = p.StandardError;
sw.AutoFlush = true;
while (!sr.EndOfStream && sr.ReadLine())
{
if (this.richTextBox1.Text != "" && richTextBox1.Text.Contains("?"))
sw.WriteLine("y");

sr.ReadLine();

richTextBox1.Text += Environment.NewLine + line;
}

the batch file the gidi.exe excute is:

ECHO "Welcome %1".
SET /P ANSWER="Do you wish to proceed (y/n) [y] ?"
IF "%ANSWER%" == "" GOTO PROCEED
IF "%ANSWER%" == "y" GOTO PROCEED
IF "%ANSWER%" == "Y" GOTO PROCEED

any help will be appreciated,

Thanks,
Gidi.