Removing printf function

I'm trying to take out the line that reads "Must enter at least one character!" from the following program of mine but I can't work out how to do it right. I thought could just take out the whole if function:
        if ( (len = noSpace(aCopy)) == 0 )
        {
            printf("Must enter at least one character!\n");
            return 0;
        }

What am I missing???

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAX 128

int noSpace(char* s)
{
    int l = 0;

    while ( *s != 0 )
    {
        if ( !isalpha(*s) )
        {
            memmove(s, s+1, strlen(s+1) + 1);
            continue;
        }
        *s = tolower(*s);
        s++;
        l++;
    }
    return l;
}

int main()
{
    char line[MAX];
    char aCopy[MAX];
    char *ptr1, *ptr2;
    int len;

    printf("Test for palindromes\n====================\n");

    while ( 1 )
    {
        printf("\nEnter string: ");
        gets(line);
        strcpy(aCopy, line);
        if ( (len = noSpace(aCopy)) == 0 )
        {
            printf("Must enter at least one character!\n");
            return 0;
        }
        for (ptr1 = aCopy, ptr2 = aCopy + len - 1; ptr1 < ptr2; ptr1++, ptr2--)
        if ( *(ptr1) != *(ptr2) )
        {
            printf("That isn't a palindrome.\n");
            break;
        }
        if ( ptr1 >= ptr2 )
        printf("That is a palindrome.\n");

        printf("\nAnother? (y|n) ");
        gets(aCopy);
        if ( tolower(aCopy[0]) == 'n' )
        break;
    }
    printf("\nGoodbye\n");
    return 0;
}