Warning: mysql_num_rows(): supplied argument is not a valid MySQL result re

[moninda]

<?php
session_start();
include("header.php");
include("conection.php");
include("modal.php");
if(isset($_SESSION["userid"]))
{
    if(isset($_GET[first])) 
    {
    }
    else
    {
        $_GET[first] =0;
    $_GET[last] = 10;
    }

    if(isset($_POST["button"]))
    {
        $resultac = mysql_query("SELECT * FROM examination");
    echo    mysql_num_rows($result);
    }
    else
    {
    $result = mysql_query("SELECT * FROM examination LIMIT $_GET[first] , $_GET[last]");
    }
$result1 = mysql_query("SELECT * FROM course LIMIT $_GET[first] , $_GET[last]");
$result2 = mysql_query("SELECT * FROM subject LIMIT $_GET[first] , $_GET[last]");
?>


<script>
function getXMLHTTP() { //fuction to return the xml http object
        var xmlhttp=false;  
        try{
            xmlhttp=new XMLHttpRequest();
        }
        catch(e)    {       
            try{            
                xmlhttp= new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch(e){
                try{
                xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
                }
                catch(e1){
                    xmlhttp=false;
                }
            }
        }

        return xmlhttp;
    }

    function getCity(strURL) {      

        var req = getXMLHTTP();

        if (req) {

            req.onreadystatechange = function() {
                if (req.readyState == 4) {
                    // only if "OK"
                    if (req.status == 200) {                        
                        document.getElementById('subdiv').innerHTML=req.responseText;                       
                    } else {
                        alert("There was a problem while using XMLHTTP:\n" + req.statusText);
                    }
                }               
            }           
            req.open("GET", strURL, true);
            req.send(null);
        }

    }
</script>

<section id="page">
<header id="pageheader" class="normalheader">
<h2 class="sitedescription">
 </h2>
</header>

<section id="contents">

<article class="post">
  <header class="postheader">
  <h2>Examination Details</h2>
  <p>&nbsp;</p>
   <?php include("selectcss.php"); ?>
  </header>
  <section class="entry">
     <p>
       <?php 
if(mysql_num_rows($resultac) >= 1)
{
    ?>
     </p>
     <table width="533" border="1">
       <tr>
    <td width="57">ExamID</td>
    <td width="66">StudentID</td>
    <td width="64">SubjectID</td>
    <td width="60">CourseID</td>
    <td width="54">Internal Type</td>
    <td width="63">Max Marks</td>
    <td width="56">Scored</td>
    <td width="61">Result</td>
    <td width="62"><strong>Action</strong></td>
  </tr>
      <?php
     $i =$_GET[first]+1;
  while($row = mysql_fetch_array($resultac))
  {
  echo "<tr>";
  echo "<td>&nbsp;"  . $i . "</td>";
          echo "<td>&nbsp;" . $row['studid'] . "</td>";
       echo "<td>&nbsp;" . $row['subid'] . "</td>";
       echo "<td>&nbsp;" . $row['courseid'] . "</td>";
         echo "<td>&nbsp;" . $row['internaltype'] . "</td>";  
         echo "<td>&nbsp;" . $row['maxmarks'] . "</td>";
         echo "<td>&nbsp;" . $row['scored'] . "</td>";
         echo "<td>&nbsp;" . $row['result'] . "</td>";
                   echo "<td>&nbsp;<a href='viewrecords.php?slid=$row[examid]&view=examination'><img  src='images/view.png' width='32' height='32' /></a> <a href='examupdate.php?exid=$row[examid]'> <img src='images/edit.png' width='32' height='32' /></a> . </td>";
  echo "</tr>&nbsp;";
  $i++;
  }
  $first=$_GET[first]-10;
$last= $_GET[last]- 10;
?>

 <tr>
          <td><?php 
    if($first <0)
    { 
    } 
    else 
    { ?><a href="examview.php?first=<?php echo $first; ?>&last=<?php echo $last; ?>">

    <?php 
    }
    ?><img src="images/previous.png" alt="" width="32" height="32" /></td>
          <td><a href="exam.php" ><img src="images/add.png" alt="" width="32" height="32" /></a></td>
           <?php 
$first=$_GET[first]+10;
$last = $_GET[last]+ 10;
?>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td>&nbsp;</td>
          <td><?php 
    if($first > mysql_num_rows($result))
    { 
    } 
    else 
    { ?>
    <a href="examview.php?first=<?php echo $first; ?>&last=<?php echo $last; ?>">
    <?php
    }
    ?><img src="images/next.png" alt="" width="32" height="32" /></td>
        </tr>

</table>
     <p>
       <?php
}
else
{
    echo "<h2>No Records Found...</h2>";
}
?>
     </p>
     <?php
     if($_SESSION["type"]=="admin")
    {
        ?>
     <p><a href="examview.php?first=<?php echo $first; ?>&amp;last=<?php echo $last; ?>"><a href="exam.php" ><strong>Add Examination Records</strong></a></p>
 <?php
    }
    ?>
  </section>
</article>


</section>


hi guys,,im having an error message appearing: it says,
,Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in C:\wamp\www\StudentInformationProject\examview.php on line 95,,
please help me debbug this,, Thank youu




<p>
  <?php 
}
else
{
        header("Location: admin.php");
}
if($_SESSION["type"]=="admin")
    {
    include("adminmenu.php");
    }
    else
    {   
    include("lecturemenu.php");
    }

include("footer.php"); ?>
</p>
<p><a href="examview.php?first=<?php echo $first; ?>&amp;last=<?php echo $last; ?>"></a></p>

[pritaeas]

Line 19 and 20. Use $result on both lines.

[moninda]

oops,,the error message is still there..tnx,,for effort,

[pritaeas]

Check the rest of the code. It's either something similar, or an error in your query. Add error checking to find out.