/*  focus-clear-value.js, version 1.0
 *  (C) 2006 Code-404 <webmaster@code-404.net>
 *
 *  "focus-clear-value.js" is freely distributable under the terms of an CC License BY-NC.
 *
/*--------------------------------------------------------------------------*/

var focusClearValue = Class.create();

focusClearValue.prototype = {
	initialize: function(id_Array) {
		this.elms = id_Array.findAll( function(setting_id) {
			return $(setting_id);
		});
		this.elms.each( this.addingEvent.bindAsEventListener(this) );
	},
	
	addingEvent: function(target_id) {
		var elm = $(target_id);
		Event.observe(elm, 'focus', this.ifDefaultValue.bindAsEventListener(this), false);
		Event.observe(elm, 'blur', this.ifValueNone.bindAsEventListener(this), false);
	},
	
	ifDefaultValue: function(event) {
		var elm = Event.element(event);
		if ($F(elm) == elm.defaultValue) {
			Field.clear(elm);
		} else {
			return;
		}
	},
	
	ifValueNone: function(event) {
		var elm = Event.element(event);
		if ($F(elm) == '') {
			elm.value = elm.defaultValue;
		} else {
			return;
		}
	}
}