) PDOException: SQLSTATE[HY093]: Invalid parameter number: parameter was not defined in C:\wamp\www\malala\insert_post.php :     Please help not able to resolve, trying since three days but not able to know what the reason its throwing me such message. (below is my complete code).

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-html -->

    <!DOCTYPE html>
    <html>
    <head>
    	<title>Insert New Post</title>
    </head>
    <body>
    <form method="post" action="insert_post.php" enctype="multipart/form-data">
    <table align="center" border="10" width="600">
    	<tr>
    		<td align="center" colspan="5" bgcolor="yellow"><h1>Insert New Post Here</h1></td>
    	</tr>

    	<tr>
    		<td align="right">Post Title:</td>
    		<td><input type="text" name="title" size="40"></td>
    	</tr>
    	<tr>
    		<td align="right">Post Author:</td>
    		<td><input type="text" name="author"></td>
    	</tr>
    	<tr>
    		<td align="right">Post image:</td>
    		<td><input type="file" name="image_name"></td>
    	</tr>
    	<tr>
    		<td align="right">Post Content:</td>
    		<td><textarea name="content" cols="50" rows="20"></textarea></td>
    	</tr>
    	<tr>
    		
    		<td align="center" colspan="5"><input type="submit" name="submit" value="Publish Now"></td>
    	</tr>

    </table>	

    </form>

    </body>
    </html>

<!-- end snippet -->

  Above Form is to insert and submit data in Database

    <?php 
include("includes/connect.php");

if (isset($_POST['submit'])) {
	
	$title = $_POST['title'];
	$datenow = date('Y/m/d');
	$author = $_POST['author'];
	$content = $_POST['content'];
	$image_name = $_FILES['image_name']['name'];
	$image_type = $_FILES['image_name']['type'];
	$image_size = $_FILES['image_name']['size'];
	$image_tmp = $_FILES['image_name']['tmp_name'];

	if ($title =='' || $author =='' || $content =='') {
		echo "<script>alert('Any feild is empty')</script>";
		exit();
	}
	if ($image_type =='image/jpeg' || $image_type =='image/png' || $image_type =='image/gif') {
		
		if ($image_size<=5000000000) {
			move_uploaded_file($image_tmp, "images/$image_name");
		}
		else{
			echo "<script>alert('Image is larger, only 50kb size is allowed')</script>";
		}
	}
	else{
		echo "<script>alert('image type is invalid')</script>";
	}

	// insert query
	   $sth = $con->prepare(" INSERT INTO posts (post_title, post_date, post_author, post_image, post_content) VALUE (:title,:datenow,:author,:image_name,:content) ");

	$sth->bindParam(':post_title', $title);
	$sth->bindParam(':post_date', $datenow);
	$sth->bindParam(':post_author', $author);
	$sth->bindParam(':post_image', $image_name);
	$sth->bindParam(':post_content', $content);

$sth->execute();
	echo "<h1>Form Submited Successfully</h1>";

}

?>

$sth->execute(); is throwing error massage as above

