if( 0 == max ) return (PRIntn)0;
PR_IMPLEMENT(PRIntn)PL_strncasecmp(const char *a, const char *b, PRUint32 max){    const unsigned char *ua = (const unsigned char *)a;    const unsigned char *ub = (const unsigned char *)b;    if( ((const char *)0 == a) || (const char *)0 == b )         return (PRIntn)(a-b);    while( max && (uc[*ua] == uc[*ub]) && ('\0' != *a) )    {        a++;        ua++;        ub++;        max--;    }    if( 0 == max ) return (PRIntn)0;    return (PRIntn)(uc[*ua] - uc[*ub]);}