D=False

while D==False:

       input=raw_input("please type 1 for 10p, 2 for 20p, 3 for 50p, 4 for 1 pound")

       while input not in ['1', '2', '3', '4']:

        print "That is not a correct coin value"
        input = raw_input("input: ")
    else:
        if input=="1":
            m=m+10
        if input=="2":
            m=m+20
        if input=="3":
            m=m+50
        if input=="4":
            m=m+100

    print("your current credit in pennys is:")
    print(m)

    D2=raw_input("are you done")
    if D2=="yes" or "Yes":
         D=True
    else:
        D=False

if D2=="yes" or "Yes":

if (D2=="yes") or "Yes":

if D2 == "yes" or "Yes":

if D2.lower() == "yes":

if D2 in ["yes", "Yes"]: