// Get the number of Drop List 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 = `createDropList $windowId`;

// Add some items to the Drop List.
addDropListItem $controlId "Item 1";
addDropListItem $controlId "Item 2";
addDropListItem $controlId "Item 3";
 
// Get the number of items
$numItems = `getNumDropListItems $controlId`;
print $numItems;