C :: Convert Elements Of String Array To Integer

I'm just learning and C. Here is a code snippit from a program that will compile. It's function is to validate credit card numbers. I have an error I can't find though. the last print statement shows the conversion in reverse string (as integers). Here is the code:

int main (void)
{
char cn[17];
char *cardtype;
int n0,n1,n2,n3,n4,n5,n6,n7,n8,n9,n10,n11,n12,n13,n14, n15;
int s1,s2,s3,s4,s5,s6,s7,s8;
int oddsum;
int sum;
int total;
int validate;
}

[code]....