not getting entries from text boxes php - php

Question

For the last couple of days I have been having an issue where my PHP code will not get the text from a form text box that has worked for 7 or 8 years. Has anyone else has this issue or is there something that may need to be running that isn't?
My PHP form is a username textbox and password textbox and submit button
this is the code that is going to the die because the username isn't being set:
if(isset($_SESSION['username'])) {
$username = $_SESSION['username'];
} else {
die('User is blank'); //$username = "";
}
this error is going to my error_log
PHP Warning: mysql_result(): Unable to jump to row 0 on MySQL result index 4 in /home/
I know I know... no mysqli
form html:
<form method="post" onsubmit="return vloginform(this);"
action="https://www..com/php_include/processlogin.php"
name="loginform">
<div id="pleft">
<div class="uandp">Username: </div><div class="inputbox"><input type="text"
name="username" maxlength="30" class="buttonsboxes" style="width: 180px;" />
</div>
<div class="uandp">Password: </div><div class="inputbox"><input
type="password" name="password" maxlength="30" class="buttonsboxes"
style="width: 180px;" /></div>
</div>
<div id="pright">
<p><input class="buttonsboxes" type="submit" value="login" name="submit"
id="submit" /><input class="buttonsboxes" type="reset" value="reset"
name="reset" id="reset" /></p>
</div>

Answer 1

Not sure how you are fetching the records but using mysql_fetch_array instead of manually fetching every column value will fix this issue. Try analysing the result before fetching it. If result is empty, skip fetching.
Something like this:
$result = mysql_query("SELECT * FROM tablename");
if (!$result || !mysql_num_rows($result)) {
die('No records.');
}
while ($row = mysql_fetch_array($result)) {
// Your code goes here
}

Answer 2

Just use the tag required in the textbox or if you are using the $_POST VARIABLE.
POST:
if(isset($_POST['username'])) {
$username = $_POST['username'];
} else {
die('User is blank'); //$username = "";
}

Answer 3

You might want to use $_REQUEST variable instead of $_SESSION variable because whenever the data is transferred from a form to php page, it is transferred in $_REQUEST variable not in $_SESSION variable.
Use can do something like:
if(isset($_REQUEST['username'])) {
$username = $_REQUEST['username'];
} else {
die('User is blank'); //$username = "";
}
UPDATE
As per your code, you are using post method to send the data, so you should you $_POST variable to get the data from the form:
$username = $_POST['username'];
and you can check whether it is empty or not by writing following line of code:
if ($username == null) {
die('User is blank'); // if username = "", this line will be executed
} else {
// do the required task...
}
I just tried the function - isset($_REQUEST['username']) and isset($_POST['username']) also, but it is not giving the desired result. But I have got above code to work.
Hope this helps:)