HTML Attribute for <INPUT ...>
BORDER =integer

BORDER is used for image submit buttons. BORDER indicates if there should be a visible border around the image. BORDER only has an effect in Netscape. MSIE does not put any visible border around image submits.

By default, Netscape puts a border around image submit buttons. By setting BORDER to zero you remove that border: 

<FORM ACTION="/cgi-bin/mycgi.pl" METHOD=POST>
name: <INPUT NAME="realname">
<INPUT TYPE=image SRC="go2.gif"
BORDER=0 HEIGHT=22 WIDTH=50 ALT="go!">
</FORM>

which gives us

name: (Form is not live)

<INPUT SRC="..."> >