Here is what I have done to show you what happen when you submit :
I completed your script to show the $_POST
var (what you click on submit) like so :
<form method="POST">
<input type="text" name="ItemName[1][2]" value="a">
<input type="text" name="ItemName[1][3]" value="b">
<input type="text" name="ItemName[1][4]" value="c">
<input type="submit">
</form>
<?php
if($_POST) {
echo "<pre>";
print_r($_POST);
echo "</pre>";
}
?>
Here is the output when I click on submit :
Array
(
[ItemName] => Array
(
[1] => Array
(
[2] => a
[3] => b
[4] => c
)
)
)
It show you that you have your array of values in $_POST["ItemName"][1]
so you can do :
$myArrayOfValues = $_POST["ItemName"][1];
I hope this will help you.