Editar el código:
ver Resultados »
Inténtalo tú mismo - ©
w3ii.com
<!DOCTYPE html> <html> <body> <p>This example uses the addEventListener() method to attach a "change" event to an input element.</p> Enter your name: <input type="text" id="fname"> <p>When you leave the input field, a function is triggered which transforms the input text to upper case.</p> <script> document.getElementById("fname").addEventListener("change", myFunction); function myFunction() { var x = document.getElementById("fname"); x.value = x.value.toUpperCase(); } </script> </body> </html>