unresolved external symbol

hi guys,
what does this error mean?

Code:

Linking...
hw1017_6.obj : error LNK2001: unresolved external symbol "int __cdecl flipacoin(int,int)" (?flipacoin@@YAHHH@Z)
Debug/hw 1017_6.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

i'm getting it when trying to run my coin toss program.

Code:

//Michele DAddio CS210
//10_17_02
//HW #6 : RANDOM


#include<iostream>
#include<cstdlib>
#include<ctime>
#include<iomanip>
using namespace std;






	//function prototype

	int flipacoin (int, int);

	void main()
	{
			int h = 0;
			int t = 0;
			int freqheads = 0;
			int freqtails = 0;

			for (int flip = 1; flip <= 10; flip++){
				cout << flipacoin(h,t) << endl;
				if(1)
					cout << "H" << endl;
				else if(0)
					cout << "T" << endl;
			  
			 
			  freqheads++;
			  freqtails++;
			}



	}


	//function definition
	int flipacoin()
	{
		
	return (rand () % 2);

	}

thanks Miche

Your flipacoin function isn't taking any parameters, even though the prototype says it should. That's your 'unresolved external symbol'.

I've noticed that the unresolved external symbol is always associated with an error in the declaration of a function, Is this true.