Find out number of vowels in a string.

//Program to find out number of vowels in a string.
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
#include<ctype.h>
void main()
{
    clrscr();
    char a[80];
    int n=0;
    cout<<"Enter a string: ";
    gets(a);
    for(int i=0;a[i]!='\0';i++)
    if(a[i]=='a'||a[i]=='e'||a[i]=='i'||a[i]=='o'||a[i]=='u')
    ++n;
    cout<<"Number of vowels in the string: "<<n;
    getch();
}