Amazon search box ammendment help needed please

I hope this is the right forum to post these kind of questions :)

How do I ammend the Amazon.co.uk (or .com) search box to only search for one type of product. In my case, I just want it to search for videos.

At the moment I've just deleted all the option value's to leave DVD and Video:

<SELECT NAME="mode">
<OPTION VALUE="video">DVD and Video
</SELECT>

But there is still a drop-down menu, albeit with only one option. How do I ammend the script to accept the OPTION VALUE=video as default and not have a drop-down menu?

I know it's a very basic ammendment, but I'm too experienced with these things :)

Thank you VERY much.

Here's my current script:

<FORM METHOD="get" ACTION="http://www.amazon.co.uk/exec/obidos/external-search">
<TABLE BORDER="0" CELLPADDING="1" cellspacing="0" BGCOLOR="#000000"><TR><TD>
<TABLE BORDER="0" CELLPADDING="2" cellspacing="0" align="center" BGCOLOR="#FFFFFF">
<TR BORDER="0">
<TD BGCOLOR="#FFFFFF" align="RIGHT" valign="middle">
<font face="verdana, arial, helvetica" size="-2"><B>
Search:</B></font></TD>
<TD BGCOLOR="#FFFFFF" align="left" valign="middle">
<font face="verdana, arial, helvetica" size="-2">
<SELECT NAME="mode">
<OPTION VALUE="video">DVD and Video
</SELECT>
</font></TD>
<TR BORDER="1">
<TD BGCOLOR="#FFFFFF" align="RIGHT" valign="middle">
<font face="verdana, arial, helvetica" size="-2"><B>
Keywords:</B></font></TD>
<TD BGCOLOR="#FFFFFF" align="left" valign="middle">
<font face="verdana, arial, helvetica" size="-2">
<INPUT TYPE="text" NAME="keyword" SIZE="10" VALUE="">
<INPUT TYPE="hidden" NAME="tag" VALUE="litmaniacom">
<INPUT TYPE="image" BORDER="0" VALUE="Go" NAME="Go" src="http://www.associmg.com/assoc/uk/pdm-search-go-btn.gif?tag-id=litmaniacom" ALIGN=absmiddle></font></TD>
</TR>