.draggable() error

.draggable() error


When I use
$(document).ready(function(){
$(".block").draggable();
});
in a test page, using the example script and "block" div and class
given by the ui.jquery.com draggable demo, everything works ok. When I
transfer exactly the same example script into my webpage (which is
already using jquery 1.2.1 successfully) I get the following error:
$(".block").draggable is not a function
(no name)()index.html (line 311)
to the wait list jQuery.readyList.push()jquery-latest.js (line 1937)
(no name)()jquery-latest.js (line 1961)
each([function(), function()], function(), undefined)jquery-latest.js
(line 585)
ready()jquery-latest.js (line 1960)
[Break on this error] $(".block").draggable();
Any ideas what's causing the error? My webpage is using the jquery
easing plugin and livequery plugin, plus my own script.
rgds, Bob