Form elements are not moving to the center

[Segadora]

I'm very new to web programming.I have a style tag inside my \[code\]head\[/code\] tag like this:\[code\]<style type="text/css"> .center { float: none; margin-left: auto; margin-right: auto; }\[/code\]And I use twitter bootstrap. I have my \[code\]form\[/code\] wrapped inside the \[code\]div\[/code\] block \[code\]<div class="center" <form> <fieldset> <legend>Legend</legend> <label>Label name</label> <input type="text" placeholder="Type something