Form buttons and text input?

Hi there,

I am trying to add a form to my post with some text inputs and buttons, these are part of a JavaScript calculator which simply multiplies the two text inputs when the button is clicked.
I insert the code into the post via text view, then when I click visual it will display these, however, when I preview the page it will not show any of these items at all?
Even a simple form with one text input won’t load e.g.


<form action="" method="post"><input name="Text1" type="text" /></form>


Any suggestions as to what I am doing wrong and how I can get around this problem.
Thanks