Input verifica multipli di 500

by Salvatore Rotondo

HTML

<input type="text" id="grammi">

CSS

.correct{
    color:#008000;
    border:solid 1px #008000;
}

.incorrect{
    color:#880000;
    border:solid 1px #880000;
}

JavaScript

document.querySelector('input#grammi').onkeyup = function() {
    if (parseInt(this.value)%500 == 0) {
        this.className = 'correct';
    }else {
        this.className = 'incorrect';
    }
};