Description:
------------
$tirepr = 30;

$name = substr("tireqty",0,-3);
$xx = $name . "pr". "<br />";
echo $$xx;


// the result is Notice: Undefined variable: tirepr

Test script:
---------------
$tirepr = "30";

$name = substr("tireqty",0,-3);
$xx = $name . "pr". "<br />";
echo $$xx;


// the result is Notice: Undefined variable: tirepr

Expected result:
----------------
print 30 

Actual result:
--------------
 Notice: Undefined variable: tirepr