'Bus Error' using fread

Hi,

I have been struggling with this one for many hours now. Code compiles fine but when I run it I get a 'bus error'. No more details are given by the program. I have narrowed it down to when I call fread.

Code:

#include <math.h>
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <vector>
#define _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES 
using namespace std;

char *wave;
char *data;
char *riff;
unsigned long int length;
unsigned int fs, numchannel, bytes, byterate, chunksize, vectsize;
short nframes, fstart, fend, comp, bits;
int toggle = 0;
int *l, *r;

...........
int main(){


//open .wav file and verify header works fine problem occurs below

...
        int *r;
        int *l;
	int left;
	int right;
	for(int i = 0; i <=50; i++){
		
		if(toggle%2 == 0){
			fread(l, 4, 1, audio);
			left = *l;
			channelL.push_back(left);
			cout <<channelL.at(left)<<endl;
			
		}
		if (toggle%2 == 1){
			fread(r, bytes, 1, audio);
			right = *r;
			channelR.push_back(right);
			cout <<channelR.at(right)<<endl;
			
		}
		toggle = toggle++;
	}
}

It works fine if I just replace left and right with k and j and increment the counters. The problem is when I call fread. I am sure it is something so obvious.

variable l is not initialized pointer,so it points nowhere. And you still hope to sucessfully write to this unknown location? you extend your luck too greately with this hope.

Thanks. I guess I didn't fully understand how to use pointers