struct undeclared (first use in this function) - c

Question

I'm very new to programming and I started to learn C. Now I just cant understand why my node structure is not visible to my functions.
I try to get some help on http://www.cprogramming.com/tutorial/c/lesson7.html
but with no luck in using code blocks 13.12
#include <stdio.h>
#include <stdlib.h>
struct node {
int data;
struct ptr * next;
};
struct node* head;
void Insert(int x)
{
struct node *temp;
temp = (node*)malloc(sizeof(struct node));
if(head == NULL)
head = temp;
temp->data = x;
temp->data = x;
temp->next = NULL;
struct node* temp1 = head;
while(temp1-> != NULL;) {
temp1 = temp1->next;
}
temp1->next = temp;
}
void print() {
struct node* temp = head;
while(temp != NULL) {
printf("the data is %d", temp->data);
temp = temp->next;
}
}
int main ()
{
head = NULL;
int a,c;
printf("How many numbers ? : \n");
scanf("%d",&a);
for(i = 0; i<a; i++); {
printf("Enter a number:\n");
scanf("%d",&c);
Insert(c);
print();
}
}

Answer 1

There are quite a few lets go one by one
number 1
struct node {
int data;
struct node *next; // chagnge ptr -> node
};
number 2
struct node *temp;
temp = malloc(sizeof(struct node)); // struct node casting
number 3
while(temp1->next != NULL) { // remove semi colum and put a next
temp1 = temp1->next;
}
number 4
int i; // for while loop
for(i = 0; i<a; i++) {
Now hopefully it compiles well, check runtime errors ( if any )
and yes
return 0; // just before main

Answer 2

you are building an infinite loop with your first element:
temp = (struct node*)malloc(sizeof(struct node));
if(head == NULL)
head = temp;
temp->data = x;
temp->next = NULL;
struct node* temp1 = head;
while(temp1->next != NULL) { // nothing to do
temp1 = temp1->next;
}
temp1->next = temp; //temp is head and temp1 is head, so head->next points to head
you should do something like
if (head == NULL) {
//fill head and leave
} else {
//traverse to the last element and concatenate the new element
}