I cannot get SoftwareSerial to work

I cannot get the software serial library to work with my arduino uno.

I tried to run the sample code from

http://arduino.cc/en/Reference/SoftwareSerial

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11); // RX, TX

void setup()  
{
  // Open serial communications and wait for port to open:
  Serial.begin(57600);



  Serial.println("Goodnight moon!");

  // set the data rate for the SoftwareSerial port
  mySerial.begin(4800);
  mySerial.println("Hello, world?");
}

void loop() // run over and over
{
  if (mySerial.available())
    Serial.write(mySerial.read());
  if (Serial.available())
    mySerial.write(Serial.read());
}

But all I get in the console window is a single line “Goonight moon”
Has anyone had this issue?

What device is D10 and D11 connected to?

Are you using 2 Arduinos. Software Serial is 1/2 duplex and cant send and receive at the same time .