<script language = "javascript">
function showSub(obj) {

    f = document.forms.select_machine;

if(obj == "1") {
   
        f.SUB1.style.display = "";
        f.SUB2.style.display = "none";
        f.SUB3.style.display = "none";
        f.SUB4.style.display = "none";
        f.SUB5.style.display = "none";
        f.SUB6.style.display = "none";
}
if(obj == "2") {
        f.SUB1.style.display = "none";
        f.SUB2.style.display = "";
        f.SUB3.style.display = "none";
        f.SUB4.style.display = "none";
        f.SUB5.style.display = "none";
        f.SUB6.style.display = "none";
     }
if(obj == "3"){
        f.SUB1.style.display = "none";
        f.SUB2.style.display = "none";
        f.SUB3.style.display = "";
        f.SUB4.style.display = "none";
        f.SUB5.style.display = "none";
        f.SUB6.style.display = "none";
     }
if(obj == "4") {
        f.SUB1.style.display = "none";
        f.SUB2.style.display = "none";
        f.SUB3.style.display = "none";
        f.SUB4.style.display = "";
        f.SUB5.style.display = "none";
        f.SUB6.style.display = "none";
     }
if(obj == "5") {
        f.SUB1.style.display = "none";
        f.SUB2.style.display = "none";
        f.SUB3.style.display = "none";
        f.SUB4.style.display = "none";
        f.SUB5.style.display = "";
        f.SUB6.style.display = "none";
     }
if(obj == "6") {
        f.SUB1.style.display = "none";
        f.SUB2.style.display = "none";
        f.SUB3.style.display = "none";
        f.SUB4.style.display = "none";
        f.SUB5.style.display = "none";
        f.SUB6.style.display = "";
     }
 }

<form name="select_machine">
<div class="input-group input-group-sm">
    <span class="input-group-addon input-group-addon-sm">상위</span>
    <select name="wr_3" id="wr_3" class="form-control input-sm required" onChange="showSub(this.options[this.selectedIndex].value);">
<option value="1" <?php echo ($write['wr_3'] == "1") ? "selected" : "";?>>1</option>
<option value="2" <?php echo ($write['wr_3'] == "2") ? "selected" : "";?>>2</option>
<option value="3<?php echo ($write['wr_3'] == "3? "selected" : "";?>>3option>
<option value="4<?php echo ($write['wr_3'] == "4? "selected" : "";?>>4option>
<option value="5" <?php echo ($write['wr_3'] == "5") ? "selected" : "";?>>5</option>
<option value="6<?php echo ($write['wr_3'] == "6") ? "selected" : "";?>>6option>
</select>
   </div>
<div class="input-group input-group-sm">
    <span class="input-group-addon input-group-addon-sm">기간</span>
<select name="SUB1" class="form-control input-sm " style="display: ;">
<option value="1-1<?php echo ($write['wr_4'] == "1-1? "selected" : "";?>>1-1</option>
<option value="1-2" <?php echo ($write['wr_4'] == "1-2") ? "selected" : "";?>>1-2</option>
</select>

<select name="SUB2" class="form-control input-sm " style="display: none;">
<option value="2-1" <?php echo ($write['wr_4'] == "2-1") ? "selected" : "";?>>2-1</option>
<option value="2-2" <?php echo ($write['wr_4'] == "2-2") ? "selected" : "";?>>2-2</option>
<option value="2-3" <?php echo ($write['wr_4'] == "2-3") ? "selected" : "";?>>2-3</option>
<option value="2-4" <?php echo ($write['wr_4'] == "2-4") ? "selected" : "";?>>2-4</option>
</select>

<select name="SUB3" class="form-control input-sm " style="display: none;">
<option value="3-1"<?php echo ($write['wr_4'] == "3-1") ? "selected" : "";?>>3-1</option>
<option value="3-2"<?php echo ($write['wr_4'] == "3-2") ? "selected" : "";?>>3-2</option>
<option value="3-3"<?php echo ($write['wr_4'] == "3-3") ? "selected" : "";?>>3-3</option>
<option value="3-4"<?php echo ($write['wr_4'] == "3-4") ? "selected" : "";?>>3-4</option>
</select>

<select name="SUB4" class="form-control input-sm " style="display: none;">
<option value="4-1"<?php echo ($write['wr_4'] == "4-1") ? "selected" : "";?>>4-1</option>
<option value="4-2"<?php echo ($write['wr_4'] == "4-2") ? "selected" : "";?>>4-2</option>
<option value="4-3"<?php echo ($write['wr_4'] == "4-3") ? "selected" : "";?>>4-3</option>
<option value="4-4"<?php echo ($write['wr_4'] == "4-4") ? "selected" : "";?>>4-4</option>
</select>

<select name="SUB5" class="form-control input-sm " style="display: none;">
<option value="5-1"<?php echo ($write['wr_4'] == "5-1") ? "selected" : "";?>>5-1</option>
<option value="5-2 "<?php echo ($write['wr_4'] == "5-2") ? "selected" : "";?>>5-2</option>
<option value="5-3"<?php echo ($write['wr_4'] == "5-3") ? "selected" : "";?>>5-3</option>
<option value="5-4"<?php echo ($write['wr_4'] == "5-4") ? "selected" : "";?>>5-4</option>
</select>

<select name="SUB6" class="form-control input-sm " style="display: none;">
<option value="6-1<?php echo ($write['wr_4'] == "6-1") ? "selected" : "";?>>6-1</option>
<option value="6-2<?php echo ($write['wr_4'] == "6-2") ? "selected" : "";?>>6-2</option>
<option value="6-3"<?php echo ($write['wr_4'] == "6-3") ? "selected" : "";?>>6-3</option>
<option value="6-4"<?php echo ($write['wr_4'] == "6-4") ? "selected" : "";?>>6-4</option>
</select>
   </div>
</form>

이 소스를 write.skin.php에 추가해서 상위 셀렉트 변경시 하위 셀렉트가 변경되는 것은 됬습니다.

그런데 view.skin.php 에 <div>하위 셀렉트 출력 : <?=$view[wr_4]?></div> 를 추가해서 작성된 글을 보면 값이 안나오더군요.. 하위 셀렉트에서 선택된 하나의 값을 출력시킬려고 하는데 어떻게 하면 될까요??