C#

// These are the Win32 error code for file not found or access denied.
const int ERROR_FILE_NOT_FOUND =2;
const int ERROR_ACCESS_DENIED = 5;

Process myProcess = new Process();
            
try
{
	myProcess.StartInfo.FileName = Application.StartupPath + "\\" + ProgramName; 
	myProcess.StartInfo.UseShellExecute = true;
	myProcess.Start();
	myProcess.WaitForExit();
}
catch (Win32Exception e)
{
	if(e.NativeErrorCode == ERROR_FILE_NOT_FOUND)
	{
		MessageBox.Show("Install file can not be located.");
	} 
	else if (e.NativeErrorCode == ERROR_ACCESS_DENIED)
	{
		// Note that if your word processor might generate exceptions
		// such as this, which are handled first.
		MessageBox.Show(ee.Message + 
			". You do not have permission to run this file.");
	}
}

public abstract class MyAbs
{
 protected MyAbs(){}

 protected MyAbs(string foo){}
}
}

public sealed class Something : MyAbs
{
 public Something(){}

 public Something(string foo){}
}

<br />
private void someMainThread() {<br />
 int ordernum = 10;<br />
 ThreadPool.QueueUserWorkItem(new WaitCallback(chkOrderstart), ordernum);<br />
}<br />
<br />
private void chkOrderstart(Object stateinfo) {<br />
 int orderNum = (Int32)stateinfo;                   //will this work???<br />
 ...<br />
}<br />