Alerting from Event
Use var from form to alert
HTML
<form id="say-form" onsubmit="return false;" action="#">
<input type="text" id="said" /><br />
<input type="submit" value="Alert Now" />
</form>
JavaScript
// Declare VARIABLES and set them same time
var form = document.getElementById( 'say-form' );
var input = document.getElementById( 'said' );
// Websites run on EVENTS
// ie: keydown, keyup, submit, etc...
// "input" will now run a function when user releases key
form.onsubmit = function() {
// alert the value of input
alert( input.value );
};