PHP - help with placing element in array please

This code is not doing what i want it to do.

I have a CSV file with 10 rows.

I explode this into an array with 10 elements.

I want to place a new element at the position '$index' (integer).

The item is actually put at the end of the array.

What's the Jack 'n' Nory?

[PHP]function writeEvent($title,$bannerName,$splashName,$link)
{
extract($GLOBALS);
$index = addEvent();
$filename = 'events.csv';
$fp = fopen($filename, "r");
$eventsData = fread($fp, filesize($filename));
fclose($fp);

$eventsArray = explode("/n", $eventsData);
$tempArray = $eventsArray;
$insert = $title.",".$bannerName.",".$splashName.",".$link.",0";
$tempArray[$index] = $insert;

$arrayString = implode("\n",$tempArray);
$filename = 'events.csv';
$fd = fopen($filename, "w");
fwrite($fd, $arrayString);
fclose($fd);
print_r($tempArray);
}[/PHP]

Array
(
[0] => Test2,ger_banner.jpg,torture.jpg,http://entslink.com,0
Test2,ger_banner.jpg,torture.jpg,http://entslink.com,1
Test2,ger_banner.jpg,torture.jpg,http://entslink.com,2
Test2,ger_banner.jpg,torture.jpg,http://entslink.com,1
Test2,ger_banner.jpg,torture.jpg,http://entslink.com,0
Test2,ger_banner.jpg,torture.jpg,http://entslink.com,0
Test2,ger_banner.jpg,torture.jpg,http://entslink.com,0
Look for this,ger_banner.jpg,torture.jpg,http://entslink.com,0
Test 3,ger_banner.jpg,torture.jpg,http://entslink.com,0
[1] => ,ger_banner.jpg,torture.jpg,http://,0
)