Functions

Recently in my C class we learned about functions and pass by reference and I have a question about a function in my programming assignment.

Code:

//Pre-conditions: numchips > 0.
//Post-conditions: Returns the cash obtained for selling
//                 numchips number of chips.
int sellchips(int *numchips_ptr)	{

	int chips_sell;
	int money_sell;
	int cash_pst_sell;
	
	printf("How many chips do you want to sell?\n");
	scanf("%d", &chips_sell);
	
	if	(*numchips_ptr > 0 && *numchips_ptr >= chips_sell)	{
		*numchips_ptr = *numchips_ptr - chips_sell;
		money_sell = chips_sell * SELL_VALUE;
		printf("$%d\n", money_sell);
	}
	else	{
		printf("Sorry, you do not have that many chips. No chips sold.\n");
	}
}

it updates the number of chips in my main fine but I'm having trouble initializing another pointer for the amount of cash the user has so i can manipulate that value.
additionally, i have the amount, money_sell, that i'm supposed to add on to cash...
i've tried multiple attempts at initializing another function with a pointer towards cash then calling it in the above function but i'm not sure how that's supposed to work out.

any help would be greatly appreciated

int sellchips(int * numchips_ptr,int * cash_ptr);
*cash_ptr +=moneysell;

haha, thats embarassing

i knew it was something silly

thank you very much