Thread: compilation error message

Hi, any help will be much appreciated.

I'm compiling with the command:
g++ -Wall -o LQueue.C Simulation.C

The message I get is:
Undefined first referenced symbol in file main

Simulation.h

Code:

#include <iostream>
#include <ctime>

#ifndef SIMULATION
#define SIMULATION

#include "LQueue.h"

class Simulation
{
  public:
    /***** Function Members *****/
	  /***** Constructor *****/
	  Simulation();
	  /*-----------------------------------------------------------
	    Construct a Simulation object.

		Precondition: None.
		Postcondition: Input data members have been initialized 
			with values entered by the user; output data members have 
			been initialized to 0; and random number generator has 
			been initialized.
	   -----------------------------------------------------------*/

	  /***** Running the simulation *****/
	  void run();
	  /*-----------------------------------------------------------
	    Run the simulation.

		Precondition: None.
		Postcondition: Simulation of airport runway management 
			has been completed and performance statistics is 
			outputted.
	   -----------------------------------------------------------*/

	  /***** Output *****/
	  void display(ostream & out);
	  /*-----------------------------------------------------------
	    Display results of the simulation.

		Precondition: ostream out is open.
		Postcondition: Simulation process is printed.

       -----------------------------------------------------------*/

	  /***** Plane processing *****/
	  void managePlanes();
	  /*-----------------------------------------------------------
	    Manage planes (if any) at the front of landing or takeoff 
		queues.  

		Precondition: freeRunway is true.
		Postcondition: Planes are dequeued and put on runway.
	   -----------------------------------------------------------*/

	  void checkForNewPlane();
	  /*---------------------------------------------------------------
	    Check if a new plane has arrived and if so, add it to the 
		takeoff queue or landing queue depending on different
		circumstances. ((STAR - on h/o))

		Precondition: none.
		Postcondition: takeoff queue or landing queue has been updated.
	   ----------------------------------------------------------------*/
  
  private:
	  /***** Data Members *****/
	    //-- Inputs
	    double takeoffRate; //in terms of hrs
		double landingRate; //in terms of hrs
		int landTimeDuration; //in terms of mins
		int takeoffTimeDuration; //in terms of mins
		int lengthOfSimulation; //in mins

		//-- Stats
		int maxPlanesInLandingQ;
		int avgTimeSpentWaitingToLand; //mins
		int maxPlanesInTakeoffQ;
		int avgTimeSpentWaitingToTakeoff; //mins


		int landingTime;
		int takeoffTime;
		bool freeRunway; //some plane is in the process of landing (or not) (if plane takesoff, it's "done") (TRIANGLED)
		int totalMinsWaitingToLand;
		int totalMinsWaitingToTakeoff;

		Queue takeoffQ;
		Queue landingQ;
};

#endif

Simulation.C

Code:

#include <iostream> // istream, ostream, >>, <<
#include <cstdlib> // rand(), srand()
#include <ctime> //time()
using namespace std;

#include "Simulation.h"

Simulation::Simulation()
{
	//-- Initialize output stats
	maxPlanesInLandingQ = 0;
	avgTimeSpentWaitingToLand = 0; //mins
	maxPlanesInTakeoffQ = 0;
	avgTimeSpentWaitingToTakeoff = 0; //mins

	freeRunway = false;
	totalMinsWaitingToLand = 0;
	totalMinsWaitingToTakeoff = 0;

	//-- get input
	cout << "Enter:/n" 
		 << "Time for a plane to land (in minutes): ";
		 cin >> landingTime; 
		 
}

void Simulation::run()
{
}

void Simulation::display(ostream & out)
{
}


void Simulation::managePlanes()
{
}

void Simulation::checkForNewPlane()
{
}

For sure, there's nothing wrong with LQueue.C and LQueue.h because I've tested those separately.

LOL It turns out I got the error because I didn't have a driver program.