You could just make:
<div style="text-align: center; border: 1px solid"> <input type="button" value="button"> </div> Or you could do it like this instead:
<div style="border: 1px solid"> <input type="button" value="button" style="display: block; margin: 0 auto;"> </div> The first one will center align everything inside the div. The other one will center align just the button.