<?php
function treeItemSelected() {
    echo "A tree item was selected.\n";
}

// Create a new button.
$button =& new GtkButton('Press Me');
// Create a new tree item
$treeItem =& new GtkTreeItem('I\'ll get selected.');

// Have the treeItemSelected function called when
// the tree item is selected.
$treeItem->connect('select', 'treeItemSelected');

// When the button is clicked the treeItemSelected
// function will be called and a message will be 
// printed to the terminal.
$button->connect('clicked', array(&$treeItem, 'select'));
?>