Validating multiple form choice

[ajna]

I am trying to validate a form....I have a drop menu populated from a table. Upon submission I want to check the chosen fields against the valid options in the table.

ie: array of numbers from database table: 1,2,3,4,5

user chooses: 2,4 (field name options[])

I know you can check a single value against an array with:

if( in_array($variable, $arr) )

but what do I set as my $arr and how do I allow for multiple $variable options?

Any help is appreciated

[NogDog]

You could use array_intersect:

<?php
$choices = array(1,2,3,4,5);
$select1 = array(1,3,5);
$select2 = array(2,4,6);
if(count(array_intersect($select1, $choices)) == count($select1))
{
   echo "<p>The first selection is valid</p>\n";
}
if(count(array_intersect($select2, $choices)) == count($select2))
{
   echo "<p>The second selection is valid</p>\n"; // does not get echoed
}
?>