selecting from an array based on form content

The following code loops through a multidimensional array, printing the subject heading and then the strand: foreach( $strandx as $subjectx=>$strandy ) { print " <li><b>".$subjectx."</b>.<br />\n"; print " <ul>\n"; asort( $strandy ); // sorts the strands foreach( $strandy as $str ) { print "<li>"; checkbox("fstrand[]",$subjectx,$str,0,0); print "</li>\n"; } print " </ul>\n"; } print "</ol>\n"; This is the array so far: $strandx = array('English' => array('Reading', 'Writing','Oral and Visual Communication'), 'Mathematics' => array('Number Sense and Numeration', 'Measurement', 'Geometry and Spatial Sense','Patterning and Algebra','Data Management and Probability')); I would like to limit the subject and strand being printed based on the subject selected in a form. So, for example, if "English" is selected in the form, only the subject name and the strands for English would be published. Could someone please help me with the code for this. Many thanks, Peter Gumbrell peter@orilla.net