insert ไม่ได้ครับ อยากให้ผู้รู้ช่วยดูว่าผมพลาดตรงส่วนไหนครับ

<?php
include_once "index.php"; 
session_start();
include "connect.php";



$cid = $_GET[id];
$grade = $_GET[grade];
/*$sql = "select * from home where h_id = ' " . $cid . " ' "; 
$result = mysql_query($sql);*/

if(isset($_POST[submit])) {
	$sql = "select * from std_material";
	$result = mysql_query($sql);
	if(mysql_num_rows($result) == "") {
		$sql2  = "insert into std_material (std_name,std_money,h_id) values ($grade,'$_POST[money]',$cid)";
	} else {
		while($rs = mysql_fetch_array($result)) {
			if($rs[h_id] != $cid){
				$sql2  = "insert into std_material (std_name,std_money,h_id) values ($grade,'$_POST[money]',$cid)";
				} else if($rs[h_id] == $cid){
					$sql2 = "update std_material set std_money = '$_POST[money]' where h_id = ' " . $cid . " ' ";
				}
			}
		}
		$result2 = mysql_query($sql2);
		if ($result2)
{?>
		<script language="JavaScript" type="text/JavaScript">
		 alert("เพิ่มข้อมูลเรียบร้อยแล้ว!!!");
		</script>
<?php
}//if
else
{?>
		<script language="JavaScript" type="text/JavaScript">
 		alert("ไม่สามารถเพิ่มข้อมูลได้!!!");
		</script>
<?php
echo "<meta http-equiv='refresh' content='0; URL=upDate_home.php?id=" . $_GET[id] . "&grade=" . $_GET[grade] . "'>";
}//else

	echo "<meta http-equiv='refresh' content='0; URL=upDate_home.php?id=" . $_GET[id] . "&grade=" . $_GET[grade] . "'>";
}
?>
<table width="600" border="0" align="center" >
<tr><td colspan = "5" align = "left"><a href = "home.php">บ้าน</a></td></tr>
</table>
<form name = "std_material" action = "" method="post"><table width="600" border="0" align="center" >
  <tr>
    <td width = "40%" align = "right" valign  = "top">วัสดุมาตราฐาน :</td>
    <td align = "left" valign  = "top">&nbsp;&nbsp;<? echo $grade; ?></td>
  </tr>
   <tr>
    <td width = "40%" align = "right" valign  = "middle">ราคา :</td>
    <td align = "left" valign  = "top">&nbsp;&nbsp;<input type = "text" name = "money" size = "15"><? echo $result[std_money]; ?>&nbsp;บาท</td>
  </tr>
  <tr>
    <td colspan = "2" align = "center" valign  = "top"><input type = "submit" name = "submit" value = "Submit"></td>
  </tr>
</table></form><br>

<table width="600" border="0" align="center"><tr><td ><hr style="background-color: rgb(204, 204, 204);" width="100%" size="1" noshade="noshade" color="#cccccc"></td></tr></table><br>

<table width="600" border="1" align="center" >
<tr><td colspan = "4" align = "left">ประเภทวัสดุที่ใช้สร้าง | <a href = "#">เพิ่มประเภทวัสดุ</a></td></tr>
  <tr>
    <td width = "20%" align = "center" valign  = "top">รหัสวัสดุ</td>
    <td width = "20%" align = "center" valign  = "top">ประเภทวัสดุ</td>
	<td width = "20%" align = "center" valign  = "top">เพิ่มรายละเอียดวัสดุ</td>
	<td width = "20%" align = "center" valign  = "top">ลบ</td>
	</td>
  </tr>

</table>