codeblocks下，怎样建立工程，进行多文件编译？如下是书上的两个文件。

parta.c文件：
#include 
void report_count ( )
void accumulate (int k);
int count = 0;
int main(void)
{
int value;
register int i;
    printf("enter a positive integer (0 to quit): ");
    while (scanf("%d", &value) == 1 && value > 0)
    {
            ++count;
            for (i = value; i >= 0; i--)
                    accumulate (i);
            printf("enter a positive integer (0 to quit): ");


    }
    report_count ( );
    return 0;
}
void report_count ( )
{
printf("loop executed %d times\n", count);
}
partb.c文件：
#include
extern int count;
void accumulate(int k)
void accumulate(int k)
{
static int subtotal = 0;
    if (k <= 0)
    {
            printf("loop cycle: %d\n", count);
            printf("subtotal: %d; total: %d\n", subtotal, total);
            subtotal = 0;

    }
    else
    {
            subtotal += k;
            total += k;

    };
}