Php Single page form processing issue - php

Question

(Sorry for my bad english)
Well, I've 3 errors in my code.
Error's:
First of all it's show : Notice: Undefined index: form in C:\xampp\htdocs\evantechbd\index.php on line 461. When i run this form.
if any error found it's show error message, well, but correct field is empty. Example: In this form there is 4 fields. a) upload image, b) select discussion c) subject and d) message. Suppose you upload a image, select a discussion and write a subject but forgot to write message. Then It's show "Message Required" and every filed is empty. I don't want empty field which is correct.
After successfully submitted the form it's show "Discussion was submitted ". But after that if i refresh the page it's send the data to database. But I did not click submit button. why this happen?
Here is my code:
<?php
if ($_POST['form'] == "Submit") {
$err = array();
$filed = addslashes($_FILES['file']['tmp_name']);
$img_named = addslashes($_FILES['file']['name']);
$img_type = addslashes($_FILES['file']['type']);
#$imgd = addslashes(file_get_contents($_FILES['file']['tmp_name']));
function getExtension($str)
{
$i = strrpos($str, ".");
if (!$i) {
return "";
}
$l = strlen($str) - $i;
$ext = substr($str, $i + 1, $l);
return $ext;
}
$extension = getExtension($img_named);
$extension = strtolower($extension);
$image_named_uniq = uniqid() . '.' . $extension;
$upload_path_dis = 'user/manage/discussionimg/';
$diss = $_POST['type'];
$sub = $_POST['sub'];
$msg = $_POST['msg'];
$date = "On " . date("F Y h:i:s A");
if (!isset($_SESSION['uname']))
$err[] = "You need to login";
else {
$uname = $_SESSION['uname']; //session username
if (empty($sub) && empty($msg) && empty($filed))
$err[] = "All field required";
else {
if (empty($sub))
$err[] = "Subject Requried";
if (empty($msg))
$err[] = "Message Requried";
if (empty($filed))
$err[] = "SORRY, you have to be upload a image";
}
}
if (!empty($err)) {
foreach ($err as $er) {
echo "<font color=red>$er</font><br/>";
}
}
else {
$sql = mysql_query("INSERT INTO discussion VALUES ('', '$imgd', '$image_named_uniq',
'$diss', '$sub', '$msg', '$uname', '$date' ) ");
if (!$sql)
echo "Can't submit your discussion" . mysql_error();
if (!move_uploaded_file($_FILES['file']['tmp_name'], $upload_path_dis . $image_named_uniq)) {
die('File Not Uploading');
} else {
echo "Discussion was submitted";
}
}
}
?>
Many Thanks for your help!!
Kanta.

Answer 1

Try changing your first if condition as follows
if (isset($_POST['submit']))
Now most of web sites uses client side validations using javascript. You can use jquery frame work to make things easier. However since you already uses validations after the POST event. You have to set values to relevant fields as bellow code. It will set tha value of the subject.
<input type="text" name="sub" value="<?php if(isset($_POST["sub"])) echo $_POST["sub"]; ?>" size="46"/>
Yes if you refresh the code it will again do the post and insert. You have to do few controls. However these things depend on your data.
a. Make unique key indexes in the database
b. Check for existing record before the insertion.
c. Redirect your page to the same page after few seconds once the user see the successful message.