int my_atox(char *bis, char *sib) /* ascii to hex by HLIM */ 
{ 
    char *p, *b; 
    char a[1]; 
    int i, sib_len, cnt; 
 
    p = sib; 
    b = bis; 
    sib_len = cnt = 0; 
    sib_len = strlen(sib); 
 
    for(i=0; i<sib_len; i++, p++) { 
        if(isalpha((int)*p)) 
            a[0] = *p - 0x57; 
        else 
            a[0] = *p - 0x30; 
 
        if(!(i%2)) { 
            *(b+(i-cnt)) = a[0]; 
            *(b+(i-cnt)) = (*(b+(i-cnt)))<<4; 
            cnt++; 
        } 
        else 
            *(b+(i-cnt)) |= a[0]; 
    } 
    return 0; 
}