I have a page which allows the user to "create a topic", open submitting this the form goes to another through a verification process which inserts the topic into the database and re-directs to back to the main page. However I want my verification page "add topic" to display an error message if all fields are not filled in. here is a my code, please can you tell me where I would need to add this validation code to notify the user to fill all fields:
// get data that sent from form
$topic=$_POST['topic'];
$detail=$_POST['detail'];
$name=$_POST['name'];
$email=$_POST['email'];
$datetime=date("d/m/y h:i:s"); //create date time
$sql="INSERT INTO $tbl_name(topic, detail, name, email, datetime)VALUES('$topic', '$detail', '$name', '$email', '$datetime')";
$result=mysql_query($sql);
if($result){
echo "Successful<BR>";
echo "<a href=main_forum.php>View your topic</a>";
}
else {
echo "ERROR";
}
mysql_close();