SRL Archive - OSR Help

i'm making a script for an advertetion site.
But if simba click on a dropdown list to open it, it cant see the dropdown list,
because it's not a part of the client,

so now i need simba to press the down arrow key,
but i can't find a function for this, scar had something like SendArrow

keydown(VK_DOWN);
wait(how long you want it down);
Keyup(VK_DOWN);