Form validation callback parameter

[eluser]Nick Roper[/eluser]
If you use array notation for form input names then an equivalent array will be created in $_POST. So, the first input named field[] can be referenced as $_POST['fiield'][0] and the next as $_POST['field'][1] etc. You can also specify keys explicitly in the input name - for example:

name="field[2]"

can then be referenced as $_POST[2]

If you want to use associative keys then don't enclose the key name in quotes in the <input> HTML, otherwise the quotes become part of the key name:

name="field[option1]"

can be referenced as $_POST['option1']