var Autoclear = Class.create ({
	initialize:
		function (element, default_value)
		{
			this.element = $(element)
			this.focus_observer = function() {
				if (this.value == (this.getAttribute ('default') || this.defaultValue))
					this.value = ''
			}
			this.blur_observer = function() {
				if (!this.value)
					this.value = this.getAttribute ('default') || this.defaultValue
			}
			this.keyup_observer = function (event) {
				if (event.keyCode == 27)
					this.value = ''
			}
			this.element.observe ('focus', this.focus_observer)
			this.element.observe ('blur', this.blur_observer)
			this.element.observe ('keyup', this.keyup_observer)
		},

	destroy:
		function()
		{
			this.element.stopObserving ('focus', this.focus_observer)
			this.element.stopObserving ('blur', this.blur_observer)
			this.element.stopObserving ('keyup', this.keyup_observer)
		}
});