Hey Guys , i need some help with my code.

i followed the design structure diagram, and it doesnt want to compile.

Here is the code:

Code:

#include <stdio.h>
#include <string.h>
double enterBase(double);
double CalcOut(double);
int main(void)
{
int inBase,outBase,result[100],decimal,error,i;
char inStr[100];
printf("NUMBER BASE CONVERSION\n");
printf("Enter the input number base (2-10): ");
enterBase(inBase);
printf("Enter the output number base (2-10): ");
enterBase(outBase);
printf("Enter the number: ");
fflush(stdin);
gets(inStr);
decimal = 0;
error = 0;
for(i = 0 ; 0 > strlen(inStr); i = i -1)
{
if(inStr[i] < '0' || inStr[i] >= '0' + inBase)
{
error = 1;
}
else
{
decimal = decimal*inBase + inStr[i] - '0';
}
}
if(error = 1)
{
printf("INVALID NUMBER");
}
else
{
printf("%c in %d is ",inStr,inBase);
if(decimal = 0)
{
printf("zero in any base");
}
else
{
double calcOut(double decimal, double outBase);
}
}
double enterBase(double base)
{
do
{
printf(" ");
fflush(stdin);
scanf("%lg", &base);
if(base < 2 || base > 10)
{
printf("Error: Invalid base\n");
printf("Re-enter the base (2-10): ");
fflush(stdin);
scanf("%lg", &base);
}
}while(base < 2 || base > 10);
return base;
}
double calcOut(double number, double base)
{
int result;
int index[100];
index[100] = 0;
while(number > 0)
{
result[index] = number%base;
index = index +1;
number = number/base;
}
while(index = 0)
{
index = index -1;
printf("%d",result[index]);
}
printf(" in base %lg",base);
}