linked list programme

[nishant123pop]

guys...
please rectify the errors while i am having with this programme
error:in create_node
proramme:
#include<iostream.h>
#include<stdio.h>
#include<stdlib.h>

class node
{
int info;
node *next;
};
node* creat_node();
void append_node(node*);
int main()
{
node *start,*ptr,*np,*newptr;
int l,ser,flag=0,n;
char ch,p;

node* creat_node()
{

ptr=(list*)malloc(sizeof(list));
if(ptr==NULL)
cout<<"overflow occured";
else
{
ptr->info=21;
ptr->next=NULL;
return ptr;
}
}
void append_node(node *np)
{
cout<<"do u want to apppend this node.. enter ur choice(y/n)";
cin>>ch;
while(ch=='y')
{
start=ptr;
start->next=ptr;
ptr->NULL;



}
}
/* search_node()
{
cout<<"enter info u want to search";
cin>>ser;
ptr=start;
while(ptr->next!=NULL)
{
if(ptr->info==ser)
{
flag=1;
break;
}
else
ptr=ptr->next;
}
if(flag==1)
cout<<"node found"
else
cout<<"node not found";


} */
cout<<"case 1: creating a node \n";
cout<<"case 2: appending a node \n";
// cout<<"case 3: searching a node \n";
cout<<"enter ur choice";
cin>>p;
do
{
switch(p)
{
case 1 :
newptr=creat_node();
break;
case 2: append_node(newptr);
break;
// case 3: ser_node();
// break;

}
}while(p=='y');
return 0;
}