Fatal error: Uncaught TypeError: Unsupported operand types: string - string in /home/siboomit/public_html/AMP/product.php:124 Stack trace: #0 [internal function]: priceC(Array, Array) #1 /home/siboomit/public_html/AMP/product.php(127): usort(Array, 'priceC') #2 {main} thrown in /home/siboomit/public_html/AMP/product.php on line 124