C program to count number of vowels in a string

#include<stdio.h>
#include<conio.h>  
#include<string.h>
void main()
{
char sk[10];
int count=0,i;
clrscr();
printf("Enter a String :");
gets(sk);
for(i=0;i<strlen(sk);i++)
switch(sk[i])
{
case 'A':
case 'E':
case 'I':
case 'O':
case 'U':
case 'a':
case 'e':
case 'i':
case 'o':
case 'u': count++;
break;
}
printf("Vowels are present in the string : %d", count);
getch();
}