I want to remove the last comma

["A. Joseph" <joefazee@xxxxxxxxx>]

This the script
$dir = "images";
$d = opendir($dir);
$out = "
var tinyMCEImageList = new Array(\n";
while(false != ($entry = readdir($d))) {
    if(preg_match("/(.jpg|.gif|.png)$/", $entry) != false) {
        $out .= "['{$entry}', '{$dir}/{$entry}'],\n";
    }

}
$out .= ");\n";

This the out put

var tinyMCEImageList = new Array(
['1_h_1.gif', 'images/1_h_1.gif'],
['1_h_2.gif', 'images/1_h_2.gif'],
['rss_2.jpg', 'images/rss_2.jpg'],
['spacer.gif', 'images/spacer.gif'],  #  I want to remove this comma
);

if the last element (['spacer.gif', 'images/spacer.gif'],) contain comma,
javascript will return error, so i want to remove it.