Comparing string to array

Hi all, Ok it's 2am, my brain has gone to mush and I am having trouble figuring out an easy way to do this, can anyone shed some light? Take a peek at the following code: // START <pre> <?php print_r($_POST); $userparam = "test['sam'][]"; // How to check if $userparam exists in the $_POST array // and get all the values from it? // Obviously this won't work, but you get the idea: if (isset($_POST[$userparam])) { echo 'yeah'; $values = $_POST[$userparam]; } else { echo 'nah'; } ?> </pre> <form method="post"> <input type="checkbox" name="test['bob'][]" value="red">red<br> <input type="checkbox" name="test['bob'][]" value="green">green<br> <input type="checkbox" name="test['bob'][]" value="blue">blue<br> <input type="checkbox" name="test['sam'][]" value="red2">red2<br> <input type="checkbox" name="test['sam'][]" value="green2">green2<br> <input type="checkbox" name="test['sam'][]" value="blue2">blue2<br> <input type="submit"> </form> // END From the code above I'm trying to figure out how to tell if the $userparam exists in the $_POST array. PHP automatically expands the form element name into multi-dim arrays within $_POST, so a simple 'isset' as shown in the code above won't play because it's got a totally useless array key passed to it. I need a way to turn the string: "test['sam'][]" into something I can look into $_POST for. Any ideas? The coffee boost is wearing off, but I want to get this licked tonight :-\ Cheers, Rich -- Zend Certified Engineer http://www.corephp.co.uk "Never trust a computer you can't throw out of a window"