Allow Javascript in posts and pages allows the include of Javascript inside posts and pages, whilst retaining HTML tags and functional script
Currently all <br /> and <p> (and its closing counterpart) tags are removed from the input code because these are the tags that WordPress automatically add.
If you want to echo a paragraph tag or a line break, or any other tag (strong, em etc) instead of enclosing them in < and > tags, enclose them in [ ] brackets for example [p] instead of <p> The square brackets are converted after the inital tags are stripped and function as normal tags.
To include square brackets in your output simply add a \ before it so [ becomes [ and ] becomes ], again these are converted and will display as [ and ]
If your question is not listed here please look on: http://www.hitreach.co.uk/wordpress-plugins/allow-javascript-in-posts-and-pages/ and if the answer is not listed there, just leave a comment