you've never used CSS (cascading style sheets), pretty fundamental part of html
anyway
put this in the <head> of your html page
<style type="text/css">
input {
font-family: Arial, Helvetica, sans-serif;
font-size: 7pt;
font-style: normal;
line-height: normal;
font-weight: normal;
font-variant: normal;
text-decoration: none;
}
</style>
then your input boxes will be the same as the one on the site you showed us, if you want it different, you can change the stuff in the style declaration, that is pretty self-explanatory