All selected rows not submitted on form submit



I have an HTML table located within a form. The first column of the table is a checkbox. When the form is submitted, it opens a popup window and calls another php file to process the selected items in the table. However, it never sends more than 1000 items from the table and I don't know why. The initial code used a GET for the form submission, which I changed to a POST, but that did not help.

Here is the form definition
<form id="scanform" method="POST" action="launchscan.php" target="scan_window">

Here if the selection box that the user chooses to kick off the process that is failing to receive all the records
        <span style="float:right;">
                Select Scan on Selected Hosts:
                <select name="scan_type">
                        <option value="ttlsearch">Title Search</option>
                        <option value="ipscan">IP Scan</option>
                <input type="button" onclick="launchscan()" value="Scan">

Here is the table definition from which rows are selected
         <table id="home" width="100%" cellspacing="0" align="center" class="display">
                        <th><input type="checkbox" onClick="toggle(this)"/></th>
                <tr class="item">
                <td><input type="checkbox" name="selected[]" value=""/></td>

Here is the JavaScript for the button call
function launchscan() {'', 'scan_window',"height=400,width=600");
        var all = document.body.getElementsByTagName("*");

Here is the snippet of code from launchscan.php. This code processes the selected rows in the HTML table. If I select over 1000 rows it never sends more than 1000. I cannot determine why.
    foreach($_POST['selected'] as $selected){
        $split = explode(':', $selected);
        $line = $split[1] . "," . $split[2] . "," . $split[0] . "\n";
    echo "Input File $filename written.<br>";
    echo "not selected\n";

If anybody can give me some insight into this I would be appreciative. I am just getting back into php and this is a bit confounding.
My suggestion would to get the PHP to work first then add the JavaScript. HTML tables should only be used to display data like a spreadsheet does and that is the only time I would use a table. I think you need to revise your logic on that part. Just my .02 cents...
Everything is working. The only issue is that, if I select more than 1000 rows I do not receive the extra rows. This was pre-existing code. I am maintaining it, I am just trying to determine why it refuses to send over 1k selected rows. Initially, I thought it was because the form was using GET, so I changed it to POST, but that did not help.
The issue was that the
was set to the default of 1000 in the php.ini file.