In-Field Labels jQuery Plugin
http://fuelyourcoding.com/scripts/infield
This is a simple plugin that turns properly formatted HTML forms into forms with in-field label support. Labels fade when the field is focussed and disappear when text entry begins. Clearing a field and leaving brings back the label.
Un plugin jquery pour obtenir le même effet que sur le formulaire de recherche de plugins.spip.net ou chrysalide.coop