widget and content alignment

I've added a Wordpress sidebar widget and that caused the content of my blog posts to be shifted downwards, resulting in a large white space where the post used t开发者_如何学运维o start. The widget is in the right place but the post content is moved down. Is there a code I can add to restore the post content back to the top?

just used this plugin http://wordpress.org/extend/plugins/html-javascript-adder/