I can update an HTML form using Javascript, when the user hits enter when on something on the form or when he triggers the onclick event on the "submit" button, but I want the form to be updated while the user is typing something.
I know that I can do Infinity loop, yet it is not a good idea; or I can check after intervals but it will cause unnecessary checking, which I don't want.
Use keyUp event handler with the input field contained within your form.
References: Javascript, jQuery
[UPDATE]
You missed round brackets at function definition, check the updated fiddle
I had the same question and based on this post and sohel's answer I managed to get it working. Now I would like to share my solution in form of a short working example: If you type your name in the first field it will suggest an email address in the second one.
<!DOCTYPE html>
<html>
<head>
<script>
function nameModify(emailElement, nameElement) {
emailElement.value = nameElement.value + '@stackoverflow.com';
}
</script>
</head>
<body>
<form name="aform" action="#">
<input type="text" name="name" onkeyup="nameModify(this.form.elements['email'], this);" >
<input type="text" name="email" >
</form>
</body>
</html>
You are looking for Autocomplete
onchangehandler