Menu driven C++ program for writing, reading a file and writing vowels in another file

#include<fstream.h>
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
#include<process.h>
#include<ctype.h>
void main()
{
   clrscr();
   int n,choice, flag;
   fstream file1,file2;
   char str[256];
   char ch;
   do
   {
      clrscr();
      cout<<"\n---MENU---\n1.Write text to the first file"
   <<"\n2.Read text from first file\n3.Write vowels to the second file"
   <<"\n4.Display the second file\n5.Exit";
      cout<<"\nEnter your choice : ";
      cin>>choice;
      switch(choice)
      {
  case 1: file1.open("smp1.txt",ios::out);
   cout<<"\nEnter the text : ";
   gets(str);
   file1<<str;
   file1.close();
   cout<<"\nFile1 Created successfully";
   break;
  case 2: file1.open("smp1.txt",ios::in);
   while(file1)
   {
      file1.get(ch);
      cout<<ch;
   }
   file1.close();
   break;
  case 3: file1.open("smp1.txt",ios::in);
   file2.open("smp2.txt",ios::out);
   while(file1.eof()==0)
   {
      file1.get(ch);
      if(ch=='a'||ch=='e'||ch=='i'||ch=='o'||ch=='u'||ch=='A'||ch=='E'||ch=='I'||ch=='O'||ch=='U')
         file2.put(ch);
   }
   file1.close();
   file2.close();
   cout<<"\nFile 2 is created with vowels from File 1";
   break;
  case 4: file2.open("smp2.txt",ios::in);
   cout<<"\nLower case vowels : ";
   flag=0;
   while(file2)
   {
      file2.get(ch);
      if(ch=='a'||ch=='e'||ch=='i'||ch=='o'||ch=='u')
      {
         cout<<ch;
         flag=1;
      }
   }
   if(flag==0)
      cout<<"\nNo lower case vowels";
   cout<<"\nUpper case vowels : ";
   flag=0;
   file2.close();
   file2.open("smp2.txt",ios::in);
   while(file2)
   {
      file2.get(ch);
      if(ch=='A'||ch=='E'||ch=='I'||ch=='O'||ch=='U')
         {
     cout<<ch;
     flag=1;
         }
   }
   if(flag==0)
      cout<<"\nNo upper case vowels";
   break;
  case 5: exit(0);
 default: cout<<"\nWrong choice!!!";
   break;
      }
      cout<<"\nPress any key to continue";
      getch();
     } while(1);
    }