Need help with a switch statement

I'm writing a program that lets a user look at and alter the manifest of a small plane. My functions are working properly but when I go through the switch statement it runs through it one more time than I need it to.

Here is my code:

Code:

---

#include "stdafx.h"
#include "string.h"

#define maxSeats 12
#define nameLength 25
 
char menuDisplay (void);
int emptySeats (void);
void listEmpty (void);
void assignSeat (void);
void deleteSeat (void);

struct seatInformation
{        unsigned int seatID;
        unsigned int seatMarker;
        char lastName[nameLength];
        char firstName[nameLength];
}        seats[maxSeats];

int _tmain(int argc, _TCHAR* argv[])
{        int i;
        for(i=0;i<maxSeats;i++)       
                seats[i].seatID = (i+1);
        for(i=0;i<maxSeats;i++)
                seats[i].seatMarker = 0;
        char decision='a';
       
        while (decision!= 'e')
        {        decision = menuDisplay();
                switch(decision)
                {        case 'A' :
                        case 'a' : printf("There are %d empty seats on this flight\n\n",emptySeats());
                                        break;
                        case 'B' :
                        case 'b' : listEmpty();
                                        break;
                        case 'C' :
                        case 'c' : assignSeat();
                                        break;
                        case 'D' :
                        case 'd' : deleteSeat();
                                        break;
                        case 'E' :
                        case 'e' : break;
                        default : printf("Invalid Entry\n");
                                break;
                }
               
                printf("\n");
        }
       
        return 0;
}

char menuDisplay (void)
{        char c;
        printf("Choose a function :\n");
        printf("  a)Show number of empty seats\n");
        printf("  b)Show list of empty seats\n");
        printf("  c)Assign a seat\n");
        printf("  d)Delete a seat assignment\n");
        printf("  e)Quit\n");
        scanf("%c",&c);
        return c;
}

int emptySeats (void)
{        int i;
        int count = 0;
        for(i=0;i<maxSeats;i++)
        {        if(seats[i].seatMarker == 0)
                        count++;
        }
        return count;
}

void listEmpty (void)
{        int i;
        for(i=0;i<maxSeats;i++)
        {        if(seats[i].seatMarker == 0)
                        printf("Seat number %d is unassigned\n",i+1);               
        }
        printf("\n");
}

void assignSeat (void)
{        int seat;
        printf("Select a seat to assign: ");
        scanf("%d", &seat);
        if(seats[seat-1].seatMarker != 1)
        {        printf("\nFill in information below to assign a passenger to seat number %d \n", seat);
                printf("Passenger first name: ");
                scanf("%s", &seats[seat-1].firstName);
                printf("Passenger last name: ");
                scanf("%s", &seats[seat-1].lastName);
                seats[seat-1].seatMarker = 1;
                printf("\nPassenger Information:");
                printf("\nSeat Number: %d\n", seat);
                printf("First Name: %s\n", seats[seat-1].firstName);
                printf("Last Name: %s\n", seats[seat-1].lastName);
                printf("SEAT CONFIRMED\n\n");
        }
        else
                printf("Seat %d is already taken", seat);
}

void deleteSeat (void)
{        int seat;
        char x[] = "";
        printf("Select a seat to delete: ");
        scanf("%d", &seat);
        if(seats[seat-1].seatMarker == 1)
        {        seats[seat-1].seatMarker = 0;
                strcpy(seats[seat-1].firstName, x);
                strcpy(seats[seat-1].lastName, x);
                printf("Seat %d has been deleted\n",seat);
        }
        else
                printf("Seat %d is not assigned\n",seat);
}

---

And here is what happens when I run:
-----------------------------------------------------------------------
Choose a function :
a)Show number of empty seats
b)Show list of empty seats
c)Assign a seat
d)Delete a seat assignment
e)Quit
a
There are 12 empty seats on this flight

Choose a function :
a)Show number of empty seats
b)Show list of empty seats
c)Assign a seat
d)Delete a seat assignment
e)Quit
Invalid Entry

Choose a function :
a)Show number of empty seats
b)Show list of empty seats
c)Assign a seat
d)Delete a seat assignment
e)Quit

-------------------------------------------------------------------------

It seems as if after it runs through the switch the first time my variable 'decision'
is getting assigned a different variable because it triggers the default switch
statement. I'm not sure what is going on so any help would be appreciated.

That's because a <enter> is two characters and scanf() is leaving the Enter key (newline) in the input buffer after you read out a single character.

Try it like this...

Code:

---

scanf(" %c",&c);

---

Note the space inserted between the " and % .... That tells scanf() to ignore invisible characters.

Thanks for the help it worked.