Use .keyup
instead of keypress.
Also use $(this).val()
or just this.value
to access the current input value.
DEMO here
Info about .keypress
from jQuery docs,
The keypress event is sent to an element when the browser registers keyboard input. This is similar to the keydown event, except in the case of key repeats. If the user presses and holds a key, a keydown event is triggered once, but separate keypress events are triggered for each inserted character. In addition, modifier keys (such as Shift) trigger keydown events but not keypress events.