// Get the number of List Box User Control items 
int $windowId;
int $controlId;
int $numItems;
 
// First create a User Window to place the Control on
$windowId = `createWindow "MyWindow"`;
 
// Create the User Control on the Window. 
$controlId = `createListBox $windowId`;
 
// Add some items to the List Box.
addListBoxItem $controlId "Item 1";
addListBoxItem $controlId "Item 2";
addListBoxItem $controlId "Item 3";
 
// Get the number of items
$numItems = `getNumListBoxItems $controlId`;
print $numItems;