plz tell why is the reason of this error :

[123 s]

#include<stdio.h>
#include<ctype.h>

typedef struct node
{
int value;
struct node *next;
struct node *prev;
}mynode ;
void add_node(struct node **head , int value);
void print_list(char *listName , struct node *head );
void getTheMiddle(mynode *head);


// The main function..
int main()
{
mynode *head ;
head = (struct node *)NULL;
add_node(&head, 1);
add_node(&head,10);
add_node(&head,9);
add_node(&head,-99);
add_node(&head,0);
add_node(&head,5);
add_node(&head,19);

print_list(" myList " , head);
getTheMiddle(head);
return 0 ;
}

//This function uses one slow and one fast
// pointer to get to the middle of the LL.
// The slow pointer is advanced only by one node
// and the fast pointer is advanced by two nodes!
void getTheMiddle(mynode *head)
{
mynode *p = head;
mynode *q = head;
if(q!=NULL)
{
while((q->next)!=NULL && (q->next->next)!=NULL)
{
p=(p!=(mynode *)NULL?p->next:(mynode *)NULL);
q=(q!=(mynode *)NULL?q->next:(mynode *)NULL);
q=(q!=(mynode *)NULL?q->next:(mynode *)NULL);
}
printf("The middle element is [%d]",p->value);
}
}
// Function to add a node
void add_node(struct node **head, int value)
{
mynode *temp, *cur;
temp = (mynode *)malloc(sizeof(mynode));
temp->next=NULL;
temp->prev=NULL;
if(*head == NULL)
{
*head=temp;
temp->value=value;
}
else
{
for(cur=*head;cur->next!=NULL;cur=cur->next);
cur->next=temp;
temp->prev=cur;
temp->value=value;
}
}
// Function to print the linked list...
void print_list(char *listName, struct node *head)
{
mynode *temp;
printf("\n[%s] -> ", listName);
for(temp=head;temp!=NULL;temp=temp->next)
{
printf("[%d]->",temp->value);
}
printf("NULL\n");
}

error: expected ‘)’ before ‘(’ token
error: expected ‘)’ before ‘*’ token

[weaknessforcats]

Beats me. There's no error in the code you posted according to Visual Studio.NET 2008.