再次发贴为为什么不能实现下拉框的三级联动

Question

请大家帮忙看下这代码为什么不能实现三级联动
代码：<?
php require("../include/Conn.php");
?>
<script language="javascript">
   
   var subcat = new Array();
   <?php
   
   $strss="select * from proclasstree where ParentsID!=0 where ParentsID=1";
   $rst=mysql_query($strss,$link);
   $nu=mysql_num_rows($rst);
   for($i=0;$i<$nu;$i++)
   {
   $arr=mysql_fetch_array($rst)
   echo"subcat[".$i."]=new Array('".$arr["ParentsID"]."','".$arr["ID"]."','".$arr["ClassName"]."');\n";
   //echo "subcat[".$i++."] = new Array('".$arr["dept_id"]."','".$arr["class"]."','".$arr["class_id"]."');\n";
   }
   ?>
    var subcat2 = new Array();
   <?php
   
   $strsss="select * from proclasstree where ParentsID!=0 where ParentsID=21";
   $rsts=mysql_query($strsss,$link);
   $nu=mysql_num_rows($rsts);
   for($i=0;$i<$nu;$i++)
   {
   $arr=mysql_fetch_array($rsts)
   echo"subcat2[".$i."]=new Array('".$arrs["ParentsID"]."','".$arrs["ID"]."','".$arrs["ClassName"]."');\n";
   //echo "subcat[".$i++."] = new Array('".$arr["dept_id"]."','".$arr["class"]."','".$arr["class_id"]."');\n";
   }
   
   ?>
   function changeselect1(locationid)
            {
             document.myform.ClassList_2.length = 0;
             document.myform.ClassList_2.options[0] = new Option('请选择','');
             for (i=0; i<subcat.length; i++)
              {
                if (subcat[i][0] == locationid)
                 {
                  document.myform.ClassList_2.options[document.myform.ClassList_2.length] = new Option(subcat[i][1], subcat[i][2]);
                 }
              }
            }
           function changeselect2(locationid)
            {
             document.myform.ClassList_3.length = 0;
             document.myform.ClassList_3.options[0] = new Option('33请选择33','');
              for (i=0; i<subcat2.length; i++)
               {
                if (subcat2[i][0] == locationid)
                {
                document.myform.ClassList_3.options[document.myform.ClassList_3.length] = new Option(subcat2[i][2], subcat2[i][1]);
                }
               }
             }
           </script>
  <select name="ClassList_1" id="ClassList_1" style="width:250px; margin:2px 0;" onchange="changeselect1(this.value)">
              <option value="">请选择</option>
  <?php
  $rs="select * from proclasstree where ParentsID=0";
  $res=mysql_query($rs,$link);
  $nu=mysql_num_rows($res);
  for($i=0;$i<$nu;$i++)
  {
  $rw=mysql_fetch_array($res);
  echo"<option value='".$rw["ID"]."'>".$rw["ClassName"]."</option>";
  }
  ?>
           </select><br/> 
<select name="ClassList_2" id="ClassList_2" style="width:250px; margin:2px 0;" onchange="changeselect2(this.value)">
<option value="">请选择</option>
         
</select>
<br/>
<select name="ClassList_3" id="ClassList_3" style="width:250px; margin:2px 0;">
<option value="">请选择</option>
</select>

Answer 1

不好意思发错了，应该是：<?
php require("../include/Conn.php");
?>
<script language="javascript">
           
           var subcat = new Array();
           <?php
           
           $strss="select * from proclasstree where ParentsID!=0 and ID=1";
           $rst=mysql_query($strss,$link);
           $nu=mysql_num_rows($rst);
           for($i=0;$i<$nu;$i++)
           {
           $arr=mysql_fetch_array($rst)
           echo"subcat[".$i."]=new Array('".$arr["ParentsID"]."','".$arr["ID"]."','".$arr["ClassName"]."');\n";
           //echo "subcat[".$i++."] = new Array('".$arr["dept_id"]."','".$arr["class"]."','".$arr["class_id"]."');\n";
           }
           ?>
            var subcat2 = new Array();
           <?php
           
           $strsss="select * from proclasstree where ParentsID!=0 and ID=21";
           $rsts=mysql_query($strsss,$link);
           $nu=mysql_num_rows($rsts);
           for($i=0;$i<$nu;$i++)
           {
           $arr=mysql_fetch_array($rsts)
           echo"subcat2[".$i."]=new Array('".$arrs["ParentsID"]."','".$arrs["ID"]."','".$arrs["ClassName"]."');\n";
           //echo "subcat[".$i++."] = new Array('".$arr["dept_id"]."','".$arr["class"]."','".$arr["class_id"]."');\n";
           }
           
           ?>
           function changeselect1(locationid)
            {
             document.myform.ClassList_2.length = 0;
             document.myform.ClassList_2.options[0] = new Option('请选择','');
             for (i=0; i<subcat.length; i++)
              {
                if (subcat[i][0] == locationid)
                 {
                  document.myform.ClassList_2.options[document.myform.ClassList_2.length] = new Option(subcat[i][1], subcat[i][2]);
                 }
              }
            }
           function changeselect2(locationid)
            {
             document.myform.ClassList_3.length = 0;
             document.myform.ClassList_3.options[0] = new Option('33请选择33','');
              for (i=0; i<subcat2.length; i++)
               {
                if (subcat2[i][0] == locationid)
                {
                document.myform.ClassList_3.options[document.myform.ClassList_3.length] = new Option(subcat2[i][2], subcat2[i][1]);
                }
               }
             }
           </script>
          <select name="ClassList_1" id="ClassList_1" style="width:250px; margin:2px 0;" onchange="changeselect1(this.value)">
              <option value="">请选择</option>
              <?php
              $rs="select * from proclasstree where ParentsID=0";
              $res=mysql_query($rs,$link);
              $nu=mysql_num_rows($res);
              for($i=0;$i<$nu;$i++)
              {
              $rw=mysql_fetch_array($res);
              echo"<option value='".$rw["ID"]."'>".$rw["ClassName"]."</option>";
              }
              ?>
           </select><br/> 
<select name="ClassList_2" id="ClassList_2" style="width:250px; margin:2px 0;" onchange="changeselect2(this.value)">
<option value="">请选择</option>
         
</select>
<br/>
<select name="ClassList_3" id="ClassList_3" style="width:250px; margin:2px 0;">
<option value="">请选择</option>
</select>

Answer 2

你的代码太长了,头晕!!~~级联的问题已经问烂了,你到google去搜个现成的吧!