C :: Linked List - Putting Info In A Struct

I'm having a little problem where after reading a file I'm unable to update my struct with some particular info. It is actually a linkedlist. This is my struct:

Code:
struct node{
int id;
char name[50];
struct node *next;
}*head;

And in my Main function:

Code:
int main(){
int i, t_id, num;
struct node *temp;
char name[50], t_name[50], input_name[50], line[LINESIZE], *value;
struct node *head = NULL;
FILE * ifp = fopen("AssignmentOneInput.txt", "r");

[Code] .....

Basically in the while loop when I input something like this for updating numbers:

Code: temp->id = num; //These are numbers separated by a comma. or this:

Code: strcpy(temp->name,value); //These are names The program crashes