Reversing of a linked list

#include<stdio.h>
#include<stdlib.h>

typedef struct node
{
 int data;
 struct node *link;
}NODE,*NODEPTR;

NODEPTR insert(NODEPTR start)
{
 NODEPTR temp;
 temp=(NODEPTR)malloc(sizeof(NODE));
 if(temp==NULL)
 {
 printf("Unsuccessful\n");
 return start;
 }
 printf("Enter the data\n");
 scanf("%d",&temp->data);
 temp->link=start;
 start=temp;
 return start;
}

NODEPTR rev(NODEPTR start)
{
 NODEPTR cur=start;
 NODEPTR prev=NULL;
 NODEPTR next;
 while(cur!=NULL)
 {
  next=cur->link;
  cur->link=prev;
  prev=cur;
  cur=next;
 }
 return prev;
}

NODEPTR disb(NODEPTR start)
{
 NODEPTR temp;
 if(start==NULL)
 {
  printf("List is empty\n");
  return;
 }
 printf("The contents of the list before reversing\n");
 for(temp=start;temp!=NULL;temp=temp->link)
  printf("%d\n",temp->data);
 return start;
}
NODEPTR disa(NODEPTR prev)
{
 NODEPTR temp;
 if(prev==NULL)
 {
  printf("list is empty\n");
  return;
 }
 printf("The contents of the list after reversing\n");
 for(temp=prev;temp!=NULL;temp=temp->link)
  printf("%d\n",temp->data);
 return prev;
}

main()
{
 int ch;
 NODEPTR start=NULL;
 NODEPTR prev=NULL;
 while(1)
 {
  printf("1.Insert into the list\n2.List before reversing\n3.Reverse the list\n4.List after reversing\n");
 scanf("%d",&ch);
 switch(ch)
 {
  case 1 : start=insert(start);break;
  case 2 : start=disb(start);break;
  case 3 : prev=rev(start);break;
  case 4 : prev=disa(prev);break;
  default : return;
 }
 }
}