c语音 银行存取余额问题

我需要编一个存取款的程序,这是我的程序,但是不能运行,希望有大神帮我写一下,有追加财富值
int main()
{
float balance; // balance
float withdraw; // withdraw money
float deposit; // deposit money
char choice; // costumer choice
printf("Please enter the old balance:\n");
scanf("%f",&balance);
do{
printf("Enter the transaction:D(Deposit);W(withdraw);F(Finished).\n");
fflush(stdin);
choice = getchar();
switch(choice)
{
case 'D':
case 'd':