Class dataBase

[plike922]

I am try to change my previous created program that get student data from 5 students and stores it into a data base. i want to make it that you can choose the amount of students to put in. I was thinking of asking for the number then changing the fix value maxElements to that number but i dont know how

#include "strlib.h"
#include "simpio.h"
#include "genlib.h"
#include "string.h"
#include <cstdlib>

#define size 100
#define maxElements 5

typedef char sting [size];

typedef struct stud // *studPtr
{
	string name;
	string address;
	string birthDate;
} *studPtr;

typedef struct studDB // *studDBPtr
{
	studPtr clas[maxElements];
	int numstuds;
} *studDBPtr;

studDBPtr initDB ();
studPtr initOneRec ();
void displayBirthDates(studDBPtr pd);
void displayPrompt();

int main()
{
	studDBPtr pdb;
	displayPrompt();
	pdb=initDB();
	displayBirthDates(pdb);
	system("pause");
}

void displayPrompt()
{
	printf("The program creates a simple data base containing students' data.\n");
	printf("The program initializes each record and displays \n");
	printf("The students' names and their birthdates.\n\n");
}

studDBPtr initDB(void)
{
	studDBPtr pd;
	studPtr pt;
	int i, maxstudents;
	printf("How many students are there: ");
	maxstudents=GetInteger();
	maxElements=maxstudents;
	pd=(studDBPtr) malloc(sizeof(*pd));
	printf("Enter student data\n");
	for(i=0; i<maxstudents; i++)
	{
		pt=initOneRec();
		pd->clas[i]=pt;
	}
	pd->numstuds=i+1;
	return(pd); 
}

studPtr initOneRec(void)
{
	studPtr pt;
	pt=(studPtr) malloc(sizeof(*pt));
	printf("Enter name: ");
	pt->name=GetLine();
	printf("Enter address: ");
	pt->address=GetLine();
	printf("Enter birth date: ");
	pt->birthDate=GetLine();
	printf("\n");
	return(pt);
}

void displayBirthDates (studDBPtr pd)
{
	int i;
	printf("The students' Birth Dates are: \n\n");
	for(i=0; i<maxElements; i++)
	{
		printf("%s \t %s\n", pd->clas[i]->name, pd->clas[i]->birthDate);
	}
}