<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
</head>
<body>
<div class="container ">
<div class="form-group">
<label for="cadena">Cadena original:</label>
<input type="text" class="form-control" id="cadena">
</div>
<div class="form-group">
<label for="cadena">Cadena a eliminar:</label>
<input type="text" class="form-control" id="quitar">
</div>
<h1 id="posicion"></h1>
<button type="button" class="btn btn-success" onclick="quitar()">Buscar</button>
<script src="js/test.js"></script>
</form>
</div>
</body>
</html>
function quitar () {
let cadena = document.getElementById('cadena').value
const quitar = document.getElementById('quitar').value
const pos = cadena.indexOf(quitar)
if (pos > -1) {
cadena = cadena.slice(0, pos) + cadena.slice(pos + quitar.length)
}
document.getElementById('posicion').innerHTML = cadena
}