whats happening!!!

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_CART 100

typedef char string15[16];
typedef char string20[21];
typedef char string50[51];
typedef char string8[9];

typedef struct {
		string20	first,middle,last;
}nameType;

typedef struct{
		nameType name;
		string50 address;
}userInfoType; //for user information

typedef struct{
		string8	code;
		int	qty;
}prodBoughtType; //for the cart

typedef prodBoughtType arrBought[MAX_CART];
struct userTag{

		string15		username,
						password;
		userInfoType	info;
		char			type;
		float			creditlimit,
						outstanding;
		arrBought		cart;
		int				nItems;
		struct userTag *pNext;
};
typedef struct userTag userType;
typedef userType * ptrUser;



void signUp (userType *pUser)
{
	char cDump, choice, cTempType = '\0';
	char arrInputCode[9];
	char arrCompareCode[9] = {"DLSU2017"};



	do{
		printf("Enter username: ");
		scanf("%s%c", (*pUser).username,&cDump); //placing the information directly within the container. Username is inside pUser
	}while (strlen((*pUser).username)<3 || strlen((*pUser).username)>15);

	do{
		printf("Enter password: ");
		scanf("%s%c", (*pUser).password,&cDump); //placing the information directly within the container. Username is inside pUser
		if (strlen((*pUser).password)<6){

			printf("Password too short, please try again. \n");
			printf("Enter password: ");
			scanf("%s%c", (*pUser).password,&cDump);
		}
		if (strlen((*pUser).password)>15){

			printf("Password too long, please try again. \n");
			printf("Enter password: ");
			scanf("%s%c", (*pUser).password,&cDump);
		}

		if (ValidPass(pUser)==1)
			pUser->password;
		else{
			printf("Error, password must contain non-letter character.\n");
			printf("Enter password: ");
			scanf("%s%c", (*pUser).password,&cDump);
		}


	}while (strlen((*pUser).password)<6 || strlen((*pUser).password)>15);





	printf("Create [S]hopper or [A]dministrator account? \n");
	printf("Input: ");
	scanf("%c%c", &cTempType, &cDump);

	if(cTempType != 's' && cTempType != 'S' && cTempType != 'a' && cTempType != 'A'){
		printf("Invalid input, please try again: \n");
		while (cTempType != 's' && cTempType != 'S' && cTempType != 'a' && cTempType != 'A'){
			printf("Input: ");
			scanf("%c%c",&cTempType, &cDump);
			}
		}


	if (cTempType == 's' || cTempType == 'S'){

		(*pUser).type = 'S';
		printf("Account Type: Shopper \n");

	}

	else if (cTempType == 'a' || cTempType == 'A'){

		printf("Input authorization code: ");
		while (strcmp(arrInputCode,arrCompareCode)!=0){
		scanf("%s%c", arrInputCode,&cDump);

			if (strcmp(arrInputCode,arrCompareCode)==0){

				(*pUser).type = 'A';
				//AdminChoice();
				printf("Account Type: Admin \n");

			}
			else {

				 printf("Invalid authorization code, try again. \n");
				 printf("Input authorization code: ");
				 scanf("%s%c", arrInputCode,&cDump);
			}
		}
	}


}

void getUserInfo (userInfoType *pInfo)
{

	printf("Enter name: \n");
	printf("First Name: ");
	fgets((*pInfo).name.first,21,stdin);
	printf("Middle Name: ");
	fgets((*pInfo).name.middle,21,stdin);
	printf("Last Name: ");
	fgets((*pInfo).name.last,51,stdin);

	printf("%s,%s,%s \n", (*pInfo).name.last,(*pInfo).name.first,(*pInfo).name.middle);




	printf("Enter address: ");
	fgets((*pInfo).address,51,stdin);
	(*pInfo).address[strlen((*pInfo).address)-1]='\0';
	(*pInfo).name.first[strlen((*pInfo).name.first)-1]='\0';
	(*pInfo).name.middle[strlen((*pInfo).name.middle)-1]='\0';
	(*pInfo).name.last[strlen((*pInfo).name.last)-1]='\0';

}


int ValidPass (userType *pUser)
{
	int i, valid=0;
	/*while (i<strlen(pUser->password)){

		if ((pUser->password[i]) < 'a' || (pUser->password[i]) > 'z')
			if ((pUser->password[i]) < 'A' || (pUser->password)[i] > 'Z')
			valid = 1;
			i++;
	}
	*/

	for(i=0;i<(strlen(pUser->password));i++){

		if (pUser->password[i] < 'a' || pUser->password[i] >'z')
			if (pUser->password[i] < 'A' || pUser->password[i] >'Z')
				valid=1;
	}
		return valid;

}

ptrUser search (ptrUser pFirst, string15 username)
{
	ptrUser pRun;

	pRun = pFirst;

	while (pRun != NULL && strcmp(username, pRun->username)!=0)
		pRun = pRun->pNext;

	return pRun;
}

void displayAll (userType *pUsers)
{
	while (pUsers!=NULL){ //stop traversing when there is no more new address

	printf("%s\n", pUsers->username);
	pUsers = pUsers->pNext; //node traversal

	}


}

void signIn (userType *pUsers)
{
	int loggedin=0;
	char arrTempUser[16], arrTempPW[16], arrInputCode[9], arrUserCode[16];
	char authcode[9]={"DLSU2017"};
	char cDump;
	ptrUser pLogin, pPassword;

	while (loggedin == 0){


	printf("Enter username: \n");
	fgets(arrTempUser,16,stdin);

	printf("Enter password: \n");
	fgets(arrTempPW,16,stdin);


	pLogin = search(pUsers, pUsers->username);
	pPassword = search(pUsers, pUsers->password);

	if (pLogin == NULL)
		printf("Not found \n");


	if (strcmp(pLogin->username, arrTempUser)==0){

			if (strcmp(pPassword->password, arrTempPW)==0){
				printf("Username is fine \n");
				printf("Password is fine");
				loggedin = 1;
		}
			else
				printf("Something is wrong with password");
			/*pPassword = search(pUsers, pUsers->password);
			if (pPassword == NULL)
				printf("Not found");*/
	}
	else printf("Something is wrong with username");

	if (pUsers->type == 'A'){

		printf("Input authorization code: ");
		scanf("%s%c", arrInputCode, &cDump);

			while (strcmp(arrInputCode,authcode)!=0){
				printf("Incorrect code, please try again: ");
				scanf("%s%c", arrInputCode, &cDump);
			}

			loggedin = 1;
			printf("Admin menu");
	}

	}

	if (pUsers->type == 'S'){

		printf("Shopper Menu");
		loggedin = 1;
	}

}


void freeAll (ptrUser *pFirst)
{
	userType *pDel;

	while(*pFirst != NULL){
		pDel = *pFirst;
		*pFirst = (*pFirst)->pNext;
		free(pDel);
	}

}

void menu (userType *pUsers, userType *pNew, userType *pLast)
{
	int opt,
		choice=0;
	char cDump;

	printf("MAIN MENU \n");
	printf("[1] Sign Up \n");
	printf("[2] Log In \n");
	printf("Choice: ");
	scanf("%d%c", &choice,&cDump);

	switch (choice){
		case 1: do {

				pNew = malloc(sizeof(userType));
				signUp(pNew);


				(*pNew).pNext = NULL;

				if (pUsers == NULL) //if initially empty
				pUsers = pNew;	//pNew is the first node
				else //connect nodes to the list
				pLast->pNext = pNew;

				pLast = pNew;
				getUserInfo (&pUsers->info);
				printf("Press [1] to create a new user or [0] to return to main menu: ");
				scanf("%d%c", &opt,&cDump);

				if (opt == 0)
					menu (pUsers, pNew, pLast);
			}while(opt == 0);

				break;

		case 2:	signIn(pUsers);
				break;
		default:freeAll(&pUsers);
				exit (0);
	}

}

int main ()
{

	userType *pUsers = NULL,
			 *pNew,
			 *pLast;
	ptrUser pRun, pTrail;
	menu (pUsers, pNew, pLast);



//displayAll(pUsers);
freeAll(&pUsers);

	return 0;
}