Permanent error in compiler using C # objects

I've used C # built-in methods to write a compiler like:

CodeDomProvider codeProvider = CodeDomProvider.CreateProvider("CSharp");
string Output = "Out.exe";
Button ButtonObject = (Button)sender;

this.RadTextBox1.Text = string.Empty;

System.CodeDom.Compiler.CompilerParameters parameters = new CompilerParameters();

//Make sure we generate an EXE, not a DLL
parameters.GenerateExecutable = true;
parameters.OutputAssembly = Output;

CompilerResults results = codeProvider.CompileAssemblyFromSource(parameters, RadTextBox1.Text);

if (results.Errors.Count > 0)
{
    RadTextBox2.ForeColor = Color.Red;
    foreach (CompilerError CompErr in results.Errors)
    {
        RadTextBox2.Text = RadTextBox2.Text +
                    "Line number " + CompErr.Line +
                    ", Error Number: " + CompErr.ErrorNumber +
                    ", '" + CompErr.ErrorText + ";" +
                    Environment.NewLine + Environment.NewLine;
    }
}

else
{
    //Successful Compile
    RadTextBox2.ForeColor = Color.Blue;

    Guid guid =            Guid.NewGuid();

    string PathToExe = Server.MapPath(Path.Combine(@"\Compiled" , Output));

    FileStream fs = System.IO.File.Create(PathToExe);

    using (StreamWriter sw = new StreamWriter(fs))
    {
        sw.Write(RadTextBox1.Text);
    }

    Response.WriteFile(PathToExe);

      

        
        
        
      

    

When I run this code and write the Main method (like example code at http://msdn.microsoft.com/en-us/library/ms228506(VS.80).aspx I get this error:

Line number 0, error number: CS5001, 'Program' c: \ Program Files \ Microsoft Visual Studio 9.0 \ Common7 \ IDE \ Out.exe 'does not contain a static method' Main 'suitable for entry point;

The above code is used as the basis for a compiler on my site (not live yet). This way you enter the code and generate the .exe assembly. But when I enter code into the text box to write code (Radtextbox1), even with the main method, I get an error.

What gives?

thanks