Sku Quick Search instead of search all fields

For performance reasons,

Need to edit the quick search to search sku, instead of all product fields.  So customer enters the sku in the search box and only the sku field is searched.  I tried to change name "keyword" to name = "sku" but that redirects to the search.asp page for some reason.  any help is appreciated, figure it must be something minor, since the search.asp page seems to be able to search only sku, when you type into the sku field from that page, and they are both processed by showsearchresults.asp.

            <form action="showsearchresults.asp" name="search" method="get" id="pcHSearchForm">

   <input type="hidden" name="pageStyle" value="<%=bType%>">

            <input type="hidden" name="resultCnt" value="<%=pcIntPreferredCountSearch%>">

   <input type="text" name="keyword" value="" id="pcHSearch">

                <input type="submit" name="submit" value="Go" id="pcHSearchSubmit">
                <div id="pcHSearchMore">
                    <a href="search.asp">Advanced Search</a>
                </div>
            </form>