seems like a simple problem to call the functions in my program but i can't figure out the parameters to use. i believe it has to deal with using new nodes and pointers. problem lies in the main function, trying to create the avl tree with the dictionary

#include <stdlib.h>
#include <malloc.h>
#include <math.h>
#include <string>
#include <stdio.h>
#include <iostream.h>
#include <fstream.h>

using namespace std;

typedef struct NODE_avl
{
char *info;
char isdeleted;
struct NODE_avl * left;
struct NODE_avl * right;
int height;
} NODE_AVL, * AVL;

int h(NODE_AVL *a);
void s_rotation_right(NODE_AVL *k2);
void s_rotation_left(NODE_AVL *k2);
NODE_AVL * search_(char *x,NODE_AVL *a);
void saving_AVL_to_file(NODE_AVL *a);
void go_through(FILE *f,NODE_AVL *a);
void create_AVL_from_file(NODE_AVL *a);
void menu();

void main()
{
menu();
int a = NULL;
malloc(a*sizeof(NODE_AVL));
create_AVL_from_file(NODE_avl);
}

void d_rotation_left(NODE_AVL *k3)
{
s_rotation_right(k3->left);
s_rotation_left(k3);
}

void d_rotation_right(NODE_AVL *k3)
{
s_rotation_left(k3->right);
s_rotation_right(k3);
}

void s_rotation_left(NODE_AVL *k2)
{
NODE_AVL *k1;
k1= k2->left;
k2->left = k1->right;
k1->right = k2;
k2->height = (h(k2->left), h(k2->right)) + 1;
k1->height = (h(k1->left), k2->height) + 1;
k2 = k1;
}

void s_rotation_right(NODE_AVL *k2)
{
NODE_AVL *k1;
k1= k2->right;
k2->right = k1->left;
k1->left = k2;
k2->height = (h(k2->right), h(k2->left)) + 1;
k1->height = (h(k1->right), k2->height) + 1;
k2 = k1;
}

int h(NODE_AVL *a)
{
if (a == NULL)
return -1;
else
return a->height;
}

void insert(char* x,NODE_AVL *a)
{
int err;
err = 0;
if (a == NULL)
/*{//create a new tree
a=malloc(sizeof(NODE_AVL));
if (a == NULL)
err = 1; //eroare_depasire_heap;
else*/
{
a->info = x;
a->isdeleted=0;
a->left = NULL;
a->right = NULL;
a->height = 0;
}
//}
else
{
if (strcmp(x,a->info)>0)
{
insert(x,a->left);
if ( h(a->left)-h(a->right) == 2)

if (strcmp(x,a->left->info)>0)
s_rotation_left(a);
else
d_rotation_right(a);
else
a->height=(h(a->left),h(a->right))+1;
}
if (strcmp(x,a->info)<0)
{
insert(x,a->right);
if ( h(a->right)-h(a->left) == 2)
{
if (strcmp(x,a->right->info)>0)
s_rotation_right(a);
else
d_rotation_left(a);
}
else
a->height=(h(a->right),h(a->left))+1;
}
}
}

int idelete(char *x,NODE_AVL *a)
{
NODE_AVL* NODEe;
NODEe = search_(x,a);
if (NODEe == NULL) return -1;
a->isdeleted=1;
return 1;
}

NODE_AVL * search_(char *x,NODE_AVL *a)
{
if (a == NULL)
return NULL;
if (strcmp(x,a->info)>0)
return search_(x,a->left);
else
if (strcmp(x,a->info)<0)
return search_(x,a->right);
else
return a;
}

void saving_AVL_to_file(NODE_AVL *a)
{
FILE *f;
if ((f = fopen("dictionary.txt","w")) == NULL)
{
printf("Error opening file");
return;
}
go_through(f,a);
}

void go_through(FILE *f,NODE_AVL *a)
{
if (a == NULL) return;
/*here insert the operation for each element;
(Example: for saving the AVL into dictionary write here
fprintf(f,"%s",a->info) where f is the file);
*/
if (!a->isdeleted) fprintf(f,"%s",a->info);
go_through(f,a->left);
go_through(f,a->right);
}

void create_AVL_from_file(NODE_AVL *a)
{
FILE *f;
char *s;
if ((f = fopen("dictionary.txt","r")) == NULL)
{
printf("Error opening file");
return;
}
while(!feof(f))
{
s=(char*)malloc(50);
fscanf(f,"%s",s);
insert(s,a);
}
}

void menu()
{
cout<<"\t\t***************************\n";
cout<<"\t\t\t== MENU ==\n"
<<"\t\t***************************\n"
<< "\nHere are your choices:\n"
<< "\n P: Print the whole dictionary.\n"
<< " A: Add a word into the dictionary.\n"
<< " D: Delete a word from the dictionary.\n"
<< " N: Count how many words contained in the dictionary.\n"
<< " C: Check spelling of a text file provided by the user.\n"
<< " Q: Exit the program.\n";
}

I may be wrong, I've not done anything with C in 3 years, but don't functions have to be defined BEFORE you can call them? ie. the main function always goes at the end of the program.

yes ur right, functions are to be defined at the beginning of the program but can be called at any time. the position of the main is irrelevent

Sorry, must have been thinking of PASCAL

no wucken furries, thanx anyways

I didn't get what you are trying to do . You can't assign NULL to an integer. Malloc is also wrong ....
From what I have understood from your code the main should be written like this

Let me explain what I have done line by line:-
1.Create a pointer of type NODE_AVL i.e, AVL root_avl;
2.ALlocate memory to it [ malloc does that even new does that but, I haven't ever used "new" ]
3.Then passing it as parameter to create_AVL_from_file

Hope this does it for you