Thread: using while getchar to flush the line

if i set up a #define FLUSH while((c=getchar()) != '\n') its quite happy with me using the macro

Code:

#include <stdio.h>
#include <stdlib.h>
#define FLUSH while((c=getchar()) != '\n')
void flush_line(void);
int main()
{
    int x = -1, y = 0;
    //char ch;

    printf("please enter a number: ");
    scanf(" %1d", &x);
    flush_line();
    printf("please enter a second number: ");
    scanf("%1d", &y);
    printf("\n x = %d and y = %d\n", x, y);
    return 0;
}

void flush_line(void)
{
    char c;
    FLUSH;
}

however if i delete the char c it doesn't work any more and i get a compiler error saying first time use of variable c.

Is there a way round this or am i doing something wrong

many thanks
coop