program does not work, what did I do wrong?

#Sample Run:

#Welcome to your commission calculator!

#( $x,xxxx >= $20000(10%), < $20000 & >= $10000(7%), < $10000(5%) )

#Please enter sales: 20000

#Your commission is $2,000.00

# Congrats!

def main():

    sales_amount = 0.0
    commission = 0.0
    total_commission = 0.0

    welcome_message()

    sales_amount = get_sales_amount()

    commission = get_commission_calc(sales_amount)
    total_commission = sales_amount * commission_percent / 100, 2

    print_totals(total_commission)

def welcome_message():

    print("Welcome to your commission calculator!")

def get_sales_amount():

    sales = 0.0
    sales = float(input("Please enter sales: "))

    return sales

def get_commission_calc(sales_amount):

    commission_percent = 0.0

    if sales >= 20000:
        commission_percent = 10
    elif sales >= 10000:
        commission_percent = 7
    else:
        commission_percent = 5

    return sales

def print_totals(total_commission):

    print("Your commission is", '${:,.2f}'.format(total_commission))

    print("\n Congrats!")

>Solution :

There were several errors:

sales_amount = 20000
def main():

    sales_amount = 0.0
    commission = 0.0
    total_commission = 0.0

    welcome_message()

    sales_amount = get_sales_amount()
    commission_percent = get_commission_calc(sales_amount) 
    total_commission = sales_amount * commission_percent / 100 #probably a typo of ", 2" and the variable name was wrong 
    
    print_totals(total_commission)
    
def welcome_message():

    print("Welcome to your commission calculator!")

def get_sales_amount():

    sales = 0.0
    sales = float(input("Please enter sales: "))

    return sales

def get_commission_calc(sales_amount):

    commission_percent = 0.0

    if sales_amount >= 20000: #variable name was wrong
        commission_percent = 10
    elif sales_amount >= 10000:
        commission_percent = 7
    else:
        commission_percent = 5

    return commission_percent #You are calculating commission percent from this function but it returned the sales

def print_totals(total_commission):

    print("Your commission is", '${:,.2f}'.format(total_commission))

    print("\n Congrats!")
    
main()