Here variable 'pass' can't parse to $_post['action']=='edit' - php

Question

<form action="" method="post">
<div class="col-md-2 ">
<input type="type" value="<?php echo $row['rcode'];?>" name="pass" id="pass"/>
<input type="submit" name="edit" class="btn btn-primary" value="edit"/>
<input type="submit" name="delete" class="btn btn-danger" value="Delete"/>
</div>
</form>
then
if($_POST['action']=='edit'){
echo $rcode1=$_REQUEST['pass'];
$sqlup="select * from transport_details where rcode='$rcode1'";

Answer 1

There is no input named action. Your current code is unreachable.
The $_POST assoc gets its keys by attribute name. E.g.
<input type="text" name="authorName" />
<?php
echo $_POST['authorName'];
?>
Your code should be like (in PHP file)
if (isset($_POST['edit'])) { ... }
OR (in HTML file)
<form action="" method="post">
<div class="col-md-2 ">
<input type="type" value="<?php echo $row['rcode'];?>" name="pass" id="pass"/>
<input type="submit" name="action" class="btn btn-primary" value="edit"/>
<input type="submit" name="action" class="btn btn-danger" value="Delete"/>
</div>
</form>

Answer 2

You can do this in your php...
if (isset($_POST['edit'])) {
echo $rcode1=$_POST['pass'];
$sqlup="select * from transport_details where rcode='".$rcode1."'";
}
assuming your html is like this...
<form action="" method="post">
<div class="col-md-2 ">
<input type="type" value="<?php echo $row['rcode'];?>" name="pass" id="pass"/>
<input type="submit" name="action" class="btn btn-primary" value="edit"/>
<input type="submit" name="action" class="btn btn-danger" value="Delete"/>
</div>
</form>
you should be able to get the value