I got an error

http://php.flashwebhost.com/sherly/medicine.php

Code:
Parse error:  syntax error, unexpected 'if' (T_IF) in /home/fwhphp/public_html/sherly/medicine.php on line 3
Code:
<?php
$overtime=40
if ($overtime<=60)
{
$pay_amount=1500;
$medicine=1000;
echo 'Pay Amount : $pay_amount : Medicine : $medicine';
}
else
{
$$pay_amount=2000;
$medicine=1700;
echo 'pay Amount : $pay_amount : Medicine : $medicine';
}