[مساعدة] خطأ عند استعراض الصفحة

السلام عليكم جميعا ً ..

هل بالإمكان مساعدتي لمعرفة سبب الخطأ الذي يظهر عند استعراض الصفحة التي تحتوي على هذا الكود

علماً بأني أستخدم Web-developer Server suite

Apche2.2

PHP5

:

<? include("connection.php");
?>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>

<body bgcolor="#FFFFFF" text="#000000">

<p> </p>
	  <table width="627" border="0" id="table1">
		<tr valign="top"> 
		  <td height="14"> 
			<table width="99%" border="0" id="table2">
			  <tr> 
				<td width="93%" valign="top"> 
				  <b><font face="Times New Roman, Times, serif" color="#FF0000">
	 *This page for system administrator only.</font></b><table width="52%" border="0" id="table3">
					<tr> 
					  <td bgcolor="DDE3E6"> 
						<table width="99%" border="0" id="table4">
						  <tr align="left"> 
		<form name="form1" method="post" action="administrator.php">
							<td width="28%" bgcolor="DDE3E6" valign="middle"><b>
	   User Name</b></td>
							<td width="65%" bgcolor="DDE3E6" valign="middle"> 
							  <input name="username" type="text" size="18" maxlength="25">
							</td>
						  </tr>
						  <tr align="left"> 
							<td width="28%" bgcolor="DDE3E6" valign="middle"><b>
	   Password</b></td>
							<td width="65%" bgcolor="DDE3E6" valign="middle"> 
							  <input name="password" type="password" size="20" maxlength="25">
							</td>
						  </tr>
		</form>
						  <tr align="left"> 
							<td width="28%" bgcolor="DDE3E6" valign="middle"> </td>
							<td width="65%" bgcolor="DDE3E6" valign="middle"> 
							  <div align="left"><img src="images/ResetButton.gif"  width="70" height="24" onClick="document.forms[0].reset()"> 
								<img src="images/EnterButton.gif"  width="70" height="24" onClick="document.forms[0].submit()"></div>
							</td>
						  </tr>
						</table>
					  </td>
					</tr>
				  </table>
				  <p> </p>
	  <?

	   if($hit == "true")
	 {
	  if(empty($username) || empty($password))
	  {
	   echo "<font face='Times New Roman, Times, serif' color='#FF0000'> please fill all fields,, </font>";
	  }
	  else if(!(preg_match("/^[a-zA-Z0-9]+$/",$username)) || !(preg_match("/^[a-zA-Z0-9]+$/",$password)))
	  {
	   echo "<font face='Times New Roman, Times, serif' color='#FF0000'> you can use alphabet and numeric values only,, </font>";
	  }
	  else
	  {
	   include("connection.php");
	   $user = $_POST['username'];
	   $pass = $_POST['password'];
	   $sql = "select * from admin where name='". $user ."' and passwd='". $pass ."'";
	   $result = execute_query($sql);
	   if(mysql_num_rows($result) != 0)
	   {
		setcookie("admin",$user);
		header('Location:view_report.php');
	   }
	   else
	   {
		echo "user name or password is not correct,,";
	   }

	  }
	 }
	  ?>
				  </td>
			  </tr>
			</table>
		  </td>
		</tr>
	  </table>

	</body>
</html>

علما بان الخطأ الذي يظهر هو:

Notice: Undefined variable: hit in C:\www\vhosts\localhost\aou\administrator.php on line 52

السطر المذكور في الخطأ هو:

if($hit == "true")