Remove Vowels Recursively

HTML

<input id="mahinput" type="text" placeholder="Remove Vowels Here" value="" />

JavaScript

function removeVowels(str) {
    if (!str) {
        return '';
    }
    var result = "",
        char = str.charAt(0);
    if (!(char === 'a' || char === 'e' || char === 'i' || char === 'o' || char === 'u')) {
        result += char;
    }
    result += removeVowels(str.substring(1));
    return result;
}

$(document).ready(function() {
    $('#mahinput').change(function() {
        alert('test');
    });
});