How Do I Fix An 'Undefined Error' Message When The Variable IS Defined?

Question

I'm getting the following on a code checker website 'E_NOTICE : type 8 -- Undefined variable: array -- at line 20' however I have defined it as $array. Any ideas?

<?php
function BubbleSort($array){
    if(count($array) > 1){
        for($i=0; $i<count($array); $i++){
            for($j=1; $j<count($array); $j++){
                $holder = $array[$j];
                if($array[$j] < $array[$j-1]) {
                    $array[$j] = $array[$j-1];
                    $array[$j-1] = $holder;
                }
            }
        }
        return $array;
    } else {
        return $array;
    }
}

echo "<br />";
print_r(BubbleSort($array));

$array = array(34534, 345122, 697979, 344365, 090);

?>