asp二级下拉代码改成php二级下拉代码。请帮一下手。谢谢！

Question

<script language = "JavaScript">
var onecount;
onecount=0;
subcat = new Array();
<?php
$count = 0;
$sql="select * from board order by classid desc ";
$result=mysql_query($sql,$conn);
while($row=mysql_fetch_array($result)){
?>
subvat[<?php echo"$count"?>] = new Array("<?php echo "$row[boardname]"?>","<?php echo "$row[classid]"?>","<?php echo "$row[boardid]"?>");
<?
$count = $count + 1;
}
$onecount=$count;
?>
function changelocation(locationid)
{document.form1.boardid.length = 0; 
 var locationid=locationid;
 var i;
 for (i=0;i < onecount; i++)
{if (subcat[i][1] == locationid)
{document.form1.boardid.options[document.form1.boardid.length] = new Option(subcat[i][0], subcat[i][2]);
}}}    
</script> 
<select name="classid" onChange="changelocation(document.form1.classid.options[document.form1.classid.selectedIndex].value)" size="1">
<option selected vaule="请选择类">请选择类</option>
<?
$csql="select * from class order by classid desc";
$cresult=mysql_query($csql,$conn);
while($crow=mysql_fetch_array($cresult)){ 
?><option  value="<? echo"$crow[classid]"?>"><? echo"$crow[classname]" ?></option>
<? 
}
?>
                    </select> <select name="boardid">
                      <option selected value="">==请选版面==</option>
                    </select>为什么不行啊？

Answer 1

subvat[<?php echo"$count"?>] = new Array("<?php echo "$row[boardname]"?>","<?php echo "$row[classid]"?>","<?php echo "$row[boardid]"?>");
<?
$count = $count + 1;
}
$onecount=$count;
?>
function changelocation(locationid)
{document.form1.boardid.length = 0; 
 var locationid=locationid;
 var i;
 for (i=0;i < onecount; i++)subvat->subcatfor (i=0;i < onecount; i++)->  for (i=0;i < <? echo"$onecount"?>; i++)