$.datepicker.setDefaults({
	showButtonPanel: true,
	beforeShow : function( input ) {
		setTimeout(function() {
			var buttonPane = $(input)
			.datepicker( "widget" )
			.find( ".ui-datepicker-buttonpane" );
			$( "<button>", {
				text: "清除",
				click: function() {
					$.datepicker._clearDate(input);
				}
			}).addClass("ui-state-default ui-priority-primary ui-corner-all").appendTo( buttonPane );
		}, 1 );
	}
});