Piston Speed Calculator

if($_POST[‘ps_rpm’] == “”) {$ps_errors++;}
else { if(!is_numeric($_POST[‘ps_rpm’])) {$ps_errors++;} }

if($ps_errors != 0) {$ps_error_msg = “Please enter proper values!”;}
else
{
$total_piston_speed = $_POST[‘ps_stroke’] * $_POST[‘ps_rpm’] / 6;
$view_total_piston_speed = ”   Piston Speed = “.$total_piston_speed;
}
}
//—————————————-
//rpm = piston speed in fpm x 6 / stroke in inches
if($_POST[‘a’] == “rpm”)
{
$rpm_stroke = $_POST[‘rpm_stroke’];
$rpm_piston_speed = $_POST[‘rpm_piston_speed’];
$rpm_errors = 0;
if($_POST[‘rpm_stroke’] == “”) {$rpm_errors++;}
else { if(!is_numeric($_POST[‘rpm_stroke’])) {$rpm_errors++;} }

if($_POST[‘rpm_piston_speed’] == “”) {$rpm_errors++;}
else { if(!is_numeric($_POST[‘rpm_piston_speed’])) {$rpm_errors++;} }

if($rpm_errors != 0) {$rpm_error_msg = “Please enter proper values!”;}
else
{
$total_rpm = $_POST[‘rpm_piston_speed’] * 6 / $_POST[‘rpm_stroke’];
$view_total_rpm = ”   RPM = “.$total_rpm;
}
}
//===============================================
$content = ‘

‘;

$content = addslashes($content);
$content = “\$result=\””.$content.”\”;”;
eval($content);
print stripslashes($result);
[/insert_php]