About the big interface created by JQuery UI...

About the big interface created by JQuery UI...

Hi everyone, I just tried the customizable jquery-ui, but in the application of $("#MyButton").button(), it created a really big button, nothing like a normal size, just like in "http://jqueryui.com/docs/Getting_Started", I didn't modified any original setting, I wonder if you can help me? or am I doing something wrong? Thanks in advice (Y)