strange error

Im doing seperate compilation and recieiving this error:

Undefined first referenced
symbol in file
Event::myFile /var/tmp/ccDP8O3f.o
Simulation:laneList /var/tmp/ccEJRun1.o
PlaneList::PlaneList(void) /var/tmp/cciNSKJz.o
Simulation::takeoffQ /var/tmp/ccKmDc8W.o
Simulation::landingQ /var/tmp/ccEJRun1.o
Simulation::eventList /var/tmp/ccEJRun1.o
ld: fatal: Symbol referencing errors. No output written to a.out
collect2: ld returned 1 exit status

now, all of them are static, although myFile is private.

Here is the Event class, since it's the only one who actually has any myFile in it.

NOTE: we have to use strsteam and not a newer version due to schools system it runs on.

Code:

#ifndef EVENT_H
#define EVENT_H
#include<string>
#include<fstream>
#include "Object.h"
#include "Plane.h"	//making an instance of plane
#include "Simulation.h"
#include "PlaneList.h"
#include "Queue.h"
#include "EventList.h"

class Event : public Object
{
	private:
		int time;
		Plane* plane;
		static ifstream myFile;
	protected:
		void setPlane(Plane* plane);
		void setTime(int time);

	public:


		void makeItHappen();
		bool getNextArrival();
		string toString();
		int getTime();
		Plane* getPlane();
		static void open(string fileName);

};






#endif


//here is the cpp file
#include <iostream>
#include <fstream>
#include <strstream>
#include "Event.h"
#include "NiceOutput.h"

#include "Arrival.h"
#include "Depart.h"
#include "Landing.h"
#include "TakeOff.h"

#include "Plane.h"	//making an instance of plane

#include "Simulation.h"

int Event::getTime()
{
	return time;
}

void Event::setTime(int time)
{
	this->time = time;
}


Plane* Event::getPlane()
{
	return plane;
}

void Event::setPlane(Plane* plane)
{
	this->plane = plane;
}


void Event::makeItHappen()
{
	//jump forward in time to the indicated event, then
	//manifest the changes made to that event.  We know what
	//time it is, so we print out that part of the output message
	//for the event first.
	cout << "Time" << NiceOutput::rightAlign(time,4) << ": Plane " << NiceOutput::rightAlign(getPlane()->getFlightNum(),2);
	//just call a method based on the event type
	if (dynamic_cast<Arrival*>(this) !=NULL)
	{
		Arrival* arrive = (Arrival*)this;
		cout<<" arrives";
		arrive->processArrival();
	}
	else if (dynamic_cast<Landing*>(this) !=NULL)
	{
		Landing* land = (Landing*)this;
		cout << " lands";
		land->processLanding();
	}
	else if (dynamic_cast<Depart*>(this) !=NULL)
	{
		Depart* departure = (Depart*)this;
		cout <<" departs";
		departure->processDeparture();
	}
	else if (dynamic_cast<TakeOff*>(this) !=NULL)
	{
		TakeOff* takeOff = (TakeOff*)this;
		cout << " takes off";
		takeOff->processTakeoff();
	}
	else
	{
		//always good to have a catch all taht will give
		//you an informative message!
		cout << "Invalid Event:";
		cout << toString();
		cout << "Halting Abnormally";

	}

}

bool Event::getNextArrival()
{
	//returns true if we successfully read the next arrival
	//from the file...
	string fileLine; //line from input text file!
	int groundTime; //min required ground time for upcoming plane
	bool success=false; //did the read work?


	//fileLine = ;
	  //this either got a string or null if no data
	if (!(Event::myFile.eof()))
	{
		//read some data
		Event::myFile >> time >> groundTime;
		  //waiting time is information about the flight itself,
		  //we need to store it in the plane data structure inside
		  //this event.
		  getPlane()->setGroundTime(groundTime);
		  success= true;
	}
	else
		success = false; //no more arrivals...

	return success;
}

string Event::toString()
{
	//give back the contents of the object in string form
	ostrstream S;
	S  <<" event for flight " << getPlane()->getFlightNum() << " at time " << time << ".";
	S.put(0);
	string line = S.str();


	return line;

}

void Event::open(string fileName)
{
	myFile.open(fileName.c_str());
}

no idea why myFile should be getting the undefined error, Ive looked over the code several times and Im probably just misreading it.

here is the mainLine

Code:

#include<iostream>
#include<fstream>
#include<string>
#include "Event.h"
#include "Simulation.h"
#include "NiceOutput.h"
#include "Queue.h"
#include "EventList.h"
#include "PlaneList.h"

#include "Arrival.h"


int main()
{


	//a few variables necessary to read in the file
	//name and set up the input file...
	string fileName = ""; //name of the file to be used!
//	ifstream myFile;

	//prompt for the desired input file name
	//bind the stream to system input, then read after prompting
	//exit with error code if we fail to do this
	cout << "Please enter input file name:";
	cin >>  fileName;


	Event::open(fileName);
	// attempt to open the data file.  Exit with error code on fail.
	//myFile.open(fileName.c_str());



	//create the necessary data structures for the simulation
	Simulation::eventList = new EventList();
	Simulation::landingQ = new Queue();
	Simulation::takeoffQ = new Queue();
	Simulation::planeList = new PlaneList();


	//prime the simulation by setting up the first arrival -
	//processing each arrival will read in the next.
	//first, make a new event...

	Event* currentEvent = (Event*)(new Arrival());

	//then attempt to get data for it...
	if (currentEvent->getNextArrival())
	{
		//there's an arrival to be processed - enter it as an event
		Simulation::eventList->insertByTime(currentEvent);

    	//run the simulation until there's nothing left in the
   		//event list - processing each arrival will cause the next future
    	//arrival to be inserted into the evne
		cout << "Simulation begins...\n\n";

		//keep going as long as the event list isn't empty.
		while (!Simulation::eventList->isEmpty())
		{
			//just get the next event and process it...
			currentEvent=Simulation::eventList->getNextEvent();
			currentEvent->makeItHappen();
		}

	 	//all events processed, just pring the final summary data.
		cout << "/n...All events complete.  Final Summary:\n";

		//NiceOutput contains all formatting routines.
		NiceOutput::headers();
		Simulation::planeList->print();
	}  //if
	else    //we are done, there was nothing in the input file.
		cout << "No arrivals in file = nothing to simulate!";
	cout << "End of Processing";

	return 1;

} //main