this my code : plz solve this problem immediately
<?php session_start();?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>GYM jobs</title>
<link href="style/style3.css" rel="stylesheet" type="text/css" />
<link rel="stylesheet" type="text/css" href="ui.dropdownchecklist.css" />
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="jquery-1.3.js"></script>
<script type="text/javascript">
$(document).ready(function() {
$('input[type="text"]').addClass("idleField");
$('input[type="text"]').focus(function() {
$(this).removeClass("idleField").addClass("focusField");
if (this.value == this.defaultValue){
this.value = '';
}
if(this.value != this.defaultValue){
this.select();
}
});
$('input[type="text"]').blur(function() {
$(this).removeClass("focusField").addClass("idleField");
if ($.trim(this.value) == ''){
this.value = (this.defaultValue ? this.defaultValue : '');
}
});
});
</script>
<script type="text/javascript" language="javascript">
function validate_required(field,alerttxt)
{
with (field)
{
if (value==null||value=="")
{
alert(alerttxt);return false;
}
else
{
return true;
}
}
}
function validate_form(thisform)
{
with (thisform)
{
if (validate_required(txtnamefit,"Name of Fitness Center must be filled out!")==false)
{txtnamefit.focus();return false;}
if (validate_required(txtcontact,"ContactPerson must be filled out!")==false)
{txtcontact.focus();return false;}
if (validate_required(txtphone,"Phone number must be filled out!")==false)
{txtphone.focus();return false;}
if (validate_required(email,"Email id must be filled out!")==false)
{email.focus();return false;}
if (validate_required(captchacode,"Word Verifications must be filled out!")==false)
{captchacode.focus();return false;}
}
}
</script>
</head>
<body>
<div class="main">
<div class="outer">
<div class="fl" style="width:440px; padding-top:8px;"><a href="index.php"><img src="images/logo.gif" width="431" height="77" border="0" /></a></div>
<div class="iconsouter"><a href="index.php" class="icon1">Home</a> | <a href="about_us.html" class="icon1">About Us</a> | <a href="vajra_fitness.html" class="icon1">Vajra School of Fitness</a> | <a href="contact_us.html" class="icon1">Contact Us</a></div>
<br/>
<br/>
</div>
<div class="outer" align="center"><img src="images/lk.gif" width="731" height="140" /><br/>
<br/>
</div>
<div class="boxouter1">
<div class="resume">
<form method="post" action="" name="emp" onsubmit="return validate_form(this)" >
<div class="textboxouter1">
<div class="reumerinner">
<table width="90%" border="0" cellspacing="0" cellpadding="0">
<tr >
<td width="33%" height="36" class="fontasall brdclr">Name :</td>
<td width="55%" class="pl8"><input type="text" id="status" name="txtnamefit" /></td>
<td width="12%"> </td>
</tr>
<tr>
<td height="36" class="fontasall brdclr">Name of Contact Person : </td>
<td style="height: 28px" class="pl8"><input type="text" id="status" name="txtcontact" /></td>
<td style="height: 28px"> </td>
</tr>
<tr>
<td height="36" class="fontasall brdclr">Address and Location :</td>
<td style="height: 32px" class="pl8">
<input type="text" id="status" name="txtadd" /></td>
<td style="height: 32px"> </td>
</tr>
<tr>
<td height="36" class="fontasall brdclr">Phone No :</td>
<td style="height: 32px" class="pl8">
<input type="text" id="status" name="txtphone" /></td>
<td style="height: 32px"> </td>
</tr>
<tr>
<td height="36" class="fontasall brdclr">Email id :</td>
<td class="pl8">
<input type="text" id="status" name="email" /></td>
<td> </td>
</tr>
<tr>
<td height="36" class="fontasall brdclr">Looking for :</td>
<td style="height: 32px" class="pl8">
<textarea name="txtlookfor" cols="" rows="" onfocus="this.style.background = 'url(images/2.gif)';" onblur="this.style.background='url(images/1.gif)';" class="textarea1" ></textarea></td>
<td style="height: 32px"> </td>
</tr>
<tr>
<td height="36" class="fontasall brdclr">Other Info :</td>
<td class="pl8">
<input type="text" id="status" name="txtother" /></td>
<td> </td>
</tr>
<tr>
<td height="43" class="fontasall brdclr">Word Verifications :</td>
<td class="pl8">
(antispam code, 3 black symbols)<br>
<table><tr><td><img src="captcha.php" alt="captcha image"></td><td><input type="text" name="captcha" size="3" maxlength="3"></td>
<td> </td>
</tr>
<tr>
</table>
</div>
<div class="textboxouter1">
<table width="827">
<tr>
<td width="630" align="center" style="height: 35px"><input name="submit" type="submit" value="" class="button1" onclick="return validate_form(this)" /></td>
<td width="185" style="height: 35px"> </td>
</tr>
</table>
</div>
</div>
</form>
</div>
</div>
<div class="footer">Copyright 2009 <span class="gym">GYM</span> Jobs. All rights reserved.</div>
</div>
</body>
</html>
<?php
if(isset($_POST["captcha"]))
if($_SESSION["captcha"]==$_POST["captcha"])
{
//CAPTHCA is valid; proceed the message: save to database, send by e-mail ...
echo 'CAPTHCA is valid; proceed the message';
}
else
{
echo 'CAPTHCA is not valid; ignore submission';
}
?>
captcha.php
<?php
session_start();
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
function _generateRandom($length=6)
{
$_rand_src = array(
array(48,57) //digits
, array(97,122) //lowercase chars
// , array(65,90) //uppercase chars
);
srand ((double) microtime() * 1000000);
$random_string = "";
for($i=0;$i<$length;$i++){
$i1=rand(0,sizeof($_rand_src)-1);
$random_string .= chr(rand($_rand_src[$i1][0],$_rand_src[$i1][1]));
}
return $random_string;
}
$im = @imagecreatefromjpeg("captcha.jpg");
$rand = _generateRandom(3);
$_SESSION['captcha'] = $rand;
ImageString($im, 5, 2, 2, $rand[0]." ".$rand[1]." ".$rand[2]." ", ImageColorAllocate ($im, 0, 0, 0));
$rand = _generateRandom(3);
ImageString($im, 5, 2, 2, " ".$rand[0]." ".$rand[1]." ".$rand[2], ImageColorAllocate ($im, 255, 0, 0));
Header ('Content-type: image/jpeg');
imagejpeg($im,NULL,100);
ImageDestroy($im);
?>