Immediate keydown change event
by MightyPork
HTML
<input type=' text' />
JavaScript
$(document).ready(function () {
var field = $("input");
field.on("keydown", function (e) {
setTimeout(function () {
if (field.val().length == 0) {
field.css('background', 'white');
} else {
field.css('background', 'yellow');
}
}, 1);
});
});