Unsupported operand types (php)

I’ve got a HUGE prob!! Got a script for resizing images php. I got the following error message :
Fatal error: Unsupported operand types in /v.www/htdocs/destinationafrica.org/includes/misc_functions.php on line 109

**
Heres m code:

**

     $size = getimagesize('old/spimages/' . $rowspic["imee"]);
                                $height = $size;
                                $width = $size;
                                if ($width > 450)
                                {
                                $width = 450;
                                $percent = ($size / $width);
                                $height = ($size / $percent);
                                }
            echo '<td rowspan="2"><img src="old/spimages/' . $rowspic['imee'] . '" height="' . $height . '" width="' . $width . '" /></td>';

Line nr. 109 is the

$percent = ($size / $width);

one.

PLEASE help! Have NO idea what this means, and can’t fins any answers on the web… Thanks in advance!