Need Transfer Value PHP - php

Question

I am creating a new website. For that website I will need to transfer a quantity and amount value from one if condition statement into another if condition statement. Both if statements are accessed by separate submit buttons named "checkamt" & "buy".
I need to transfer the "quantity", "value", and "net" values to and from the checkamt if statement to the buy if statement.
Here's my code:
<form action="index.php" method="post">
<input type="submit" name="checkamt" value="Check Amount"/>
<input type="submit" name="buy" value="Buy"/>
</form>
<?php
if(isset($_POST[checkamt]))
{
$qun=1;
$val=5000;
$total=$qun*$val;
}
if(isset($_POST[buy]))
{
echo $qun;
echo $val;
echo $total;
}
?>

Answer 1

I think that the problem you're having is that variables don't persist on page change. If you want that, you'll need to use a session. First, you must call session_start before anything, including HTML, is sent to the user. Then, you can use the $_SESSION variable.
<?php
session_start();
?>
<form action="index.php" method="post">
<input type="submit" name="checkamt" value="Check Amount"/>
<input type="submit" name="buy" value="Buy"/>
</form>
<?php
if(isset($_POST[checkamt]))
{
$_SESSION['qun']=1;
$_SESSION['val']=5000;
$_SESSION['total']=$qun*$val;
}
if(isset($_POST[buy]))
{
echo $_SESSION['qun'];
echo $_SESSION['val'];
echo $_SESSION['total'];
}
?>

Answer 2

Improve your English! Not sure if this is what you want, but if you want to share the values of your variables between the two ifs? You have to declare them at a higher scope than your if:
<?php
$qun = 0;
$val = 0;
$total = 0;
if(isset($_POST[checkamt]))
{
$qun=1;
$val=5000;
$total=$qun*$val;
}
if(isset($_POST[buy]))
{
echo $qun;
echo $val;
echo $total;
}
?>

Answer 3

Not sure if I'm getting the question right, but why not do something like this :
if(isset($_POST[checkamt]) || isset($_POST[buy]))
{
$qun=1;
$val=5000;
$total=$qun*$val;
echo $qun;
echo $val;
echo $total;
}

Answer 4

You need to track your variables between the different forms. You can use SESSION like Xeon06 suggested, or do the following. I'm only showing for $qun:
<?php
if(isset($_POST['checkamt'])) {
$qun=1;
}
if(isset($_POST['buy'])) {
echo $qun;
}
?>
<form action="index.php" method="post">
<input type="hidden" name="qun" value="<?php echo $qun; ?>" />
<input type="submit" name="checkamt" value="Check Amount"/>
<input type="submit" name="buy" value="Buy"/>
</form>