Help with SEND on a macro autoit script.

$money = Send("4999")

Sleep(500)
Send ("{i down}");inventory
Sleep(250)
send ("{i up}")
MouseMove(663, 406, 1);pet tab
Sleep(250)
MouseClick("left")
Sleep(250)
MouseMove(1137, 992, 1);bottom button
sleep(250)
MouseMove(1138, 914, 2);black market button
Sleep(250)
MouseClick("left");select black market
Sleep(250)
MouseMove(148, 134, 1);moves to list
Sleep(250)
MouseClick("left");clicks list
Sleep(250)
MouseMove(814, 271, 1);moves to pet #2
Sleep(250)
MouseDown("left");selects pet #2
Sleep(250)
MouseMove(143, 206, 1);drags pet#2
Sleep(500)
MouseUp("left");Drops pet#2
Sleep(250)
Send($money)