Thread: homework help intro to c

Hello I'm doing an app purchasing program and my setcost function will only print the the cost of one the apps for whatever I input. My program is not finished yet, so not all my function definitions have been defined. Thank you for your help.

Code:

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <ctype.h>


// Displays the list of apps available
//prompts for the user’s selection and sets the value of the selection
void DisplayApps(char *selectionPtr);


//sets the cost of the item based on value stored in purchase
void SetCost(char selection, double *costPtr);


//Displays the codes for the user to input money - gets user input amounts
//compares the int codes and updates the deposit amount
void PaymentOptions(double *depositPtr, double cost);


//compares the amount the user has in deposits to the price of app selected.
//It returns 1 if the amount is enough to cover the cost, 0 if there is not enough.
int Compare(double deposit, double choiceCost);


//uses PaymentOptions function to display and collect dollar amounts from the user
//uses Compare function to keep comparing the added deposited amount to the item cost.
void Pay(double *depositPtr, double choiceCost);


//calculates the amount of leftover from your deposits
void GetChange(double *depositPtr, double choiceCost);


//Asks the user if they want another app
void DoItAgain(char *quitPtr);




int main()
{
	char again, selection;
	double cost;


	printf("Welcome To The App Store\n");
	printf("***********************************\n");
	do {
		// Amount of money
		//Display the Apps
		DisplayApps(&selection);
		SetCost(selection, &cost);
		printf("cost is %.2lf\n", cost);
		DoItAgain(&again);
	} while (again == 'Y');


	return 0;
}


void DoItAgain(char *quitPtr)
{
	printf("Do you want to make another purchase?\n");
	scanf(" %c", quitPtr);
	*quitPtr = toupper(*quitPtr);
}


void DisplayApps(char *selectionPtr)
{
	printf("Here are your selections:\n\n");
	printf("C -- Clown Punching         $299.99\n");
	printf("V -- Virtual Snow Globe     $249.99\n");
	printf("R -- Remote PC              $999.99\n");
	printf("G -- Grocery List Helper    $2.99\n");
	printf("M -- Mobile Cam Viewer      $89.99\n\n\n");
	printf("Please enter a selection\n");
	scanf(" %c", selectionPtr);
	*selectionPtr = toupper(*selectionPtr);
	printf("Your selection was: %c\n", *selectionPtr);
	printf("-------------------------------------------------\n");
}


void SetCost(char selection, double *costPtr)
{
	if (selection = 'C')
	{
		*costPtr = 299.99;
	 }
	else if (selection = 'V')
	{
		*costPtr = 249.99;
	}
	else if (selection = 'R')
	{
		*costPtr = 999.99;
	}
	else if (selection = 'G')
	{
		*costPtr = 2.99;
	}
	else if (selection = 'M')
	{
		*costPtr = 89.99;
	}
}

Thank for your help