c - Binary tree, cannot free memory -

i've made binary tree (bst) , works fine, can't free allocated memory. nodes made of pointers (left, right, parent) , data, first name, name , phone number. first name , name static char arrays, , phone number of int , it's key tree. use function free memory:

void freeyourtree(node* x) {     if (!x)         return;     freeyourtree(x->left);     freeyourtree(x->right);     free(x);     x = null; } 

but when use function , show tree inorder still shows records trash chars instead of first name. can't find what's wrong that. give insert function:

void insert(node** root) {     node* x = (node*) malloc(sizeof(node));     if (x == null)     {         printf("malloc error");         return;     }     printf("put first name: ");     scanf("%s", x->f_name);     printf("put name: ");     scanf("%s", x->s_name);     printf("put number: ");     scanf("%ld", &(x->number));     x->left = null;     x->right = null;     x->parent = null;      node* = null;     node* walk = *root;     while (walk != null)     {         = walk;         if (x->number < walk->number)         {             walk = walk->left;         } else {             walk = walk->right;         }     }     x->parent = a;     if (a == null)     {         *root = x;         return;     }     if (x->number < a->number)     {         a->left = x;     } else {         a->right = x;     } } 

everything else works fine - showing inorder, showing max , min (everything recurrent), searching, counting nodes , tree height, looks free(x) freeing static first name char array, first variable in struct definition. here structure:

typedef struct wezel {     char f_name[size];     char s_name[size];     long int number;     struct wezel* left;     struct wezel* right;     struct wezel* parent; } node; 

size defined 64. thank help, i'm stuck :(