게시판질문좀 드리겠습니다

게시판 검색후 링크를 보면

&sca=&sop=and&sfl=wr_subject&stx=타란

이런식으로 나오더라구요 

대충 여기 부분인거같은데요

<fieldset id="bo_sch">
    <legend>게시물 검색</legend>

    <form name="fsearch" method="get">
    <input type="hidden" name="bo_table" value="<?php echo $bo_table ?>">
    <input type="hidden" name="sca" value="<?php echo $sca ?>">
    <input type="hidden" name="sop" value="and">
    <label for="sfl" class="sound_only">검색대상</label>
    <select name="sfl" id="sfl">
        <option value="wr_subject"<?php echo get_selected($sfl, 'wr_subject', true); ?>>제목</option>
        <option value="wr_content"<?php echo get_selected($sfl, 'wr_content'); ?>>내용</option>
        <option value="wr_subject||wr_content"<?php echo get_selected($sfl, 'wr_subject||wr_content'); ?>>제목+내용</option>
        <option value="mb_id,1"<?php echo get_selected($sfl, 'mb_id,1'); ?>>회원아이디</option>
        <option value="mb_id,0"<?php echo get_selected($sfl, 'mb_id,0'); ?>>회원아이디(코)</option>
        <option value="wr_name,1"<?php echo get_selected($sfl, 'wr_name,1'); ?>>글쓴이</option>
        <option value="wr_name,0"<?php echo get_selected($sfl, 'wr_name,0'); ?>>글쓴이(코)</option>
    </select>
    <input name="stx" value="<?php echo stripslashes($stx) ?>" placeholder="검색어(필수)" required id="stx" class="sch_input" size="15" maxlength="20">
    <button type="submit" value="검색" class="sch_btn"><i class="fa fa-search" aria-hidden="true"></i> <span class="sound_only">검색</span></button>
    </form>
</fieldset>

만약에 주소에서 추가적으로

bo_table=road&wr_1=&wr_2=&wr_3=&wr_4=&wr_5=&sca=&sop=and&sfl=wr_subject&stx=타란

위주소와 같이 나오게 하고싶은데 

아래를 추가하고싶은데 어떻게 해야할까요 ㅜ?

&wr_1=<?=$_GET['wr_1']?>&wr_2=<?=$_GET['wr_2']?>&wr_3=<?=$_GET['wr_3']?>