Write a value-returning function, isVowel, that returns the value true if a given character is a vowel and otherwise returns false.

***Collect the user's input in the main() and pass it to the isVowel() function. isVowel() function returns true or false.

***Use Call-by-Value (value returning function).

***Validate the user's input (allow only alphabet characters: a through z, or A through Z).

***Allow the user to repeat the program.

OUTPUTS:

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Enter an alphabet character: 2

Invalid input.

Please try again.

Enter an alphabet character:

**********************************

Enter an alphabet character: a

a is a vowel: 1

Do you want to repeat this program?
y/n
> y

**********************************

Enter an alphabet character: E

E is a vowel: 1

Do you want to repeat this program?
y/n
> y

**********************************

Enter an alphabet character: B

B is a vowel: 0

Do you want to repeat this program?
y / n
> n