HTML tag checker

Hi All,

I'm having a text area in my rails application as <%= f.text_area :text
%>. User allowed to enter HTML tags in that text area. I'm facing
following problems:

1) Not able to check whether the HTML tags entered by user are correct
or not i.e how to check whether the HTML tags are properly closed or not

2) If the user copies the source code of any site and pastes it into
above text field, the layout distracts.

Suggestions Appreciated........

Thanks and Regards

Saurabh Peshkar