C program to check whether input alphabet is a vowel or not using function

#include <stdio.h>

int main()
{
  char ch;
  int flg;

  printf("Input a character : ");
  scanf("%c",&ch);
  flg=check_vowel(ch);
  if(flg==1)
  printf("%c is a vowel",ch);
  else
  printf("%c is not a vowel",ch);
  return 0;
}
int check_vowel(char a)
{

    if (a=='a'||  a == 'e'||  a == 'i'||  a == 'o'||  a == 'u'||a=='A'||  a == 'E'||  a == 'I'||  a == 'O'||  a == 'U')
       return 1;

    return 0;
}

/*

Output : #1

Input a character :A
A is a vowel


Output : #2
Input a character :x
x is not a vowel
*/