Delay 1000
SetEnvironmentVar "Key","65"
BeginThread "Thread1"
While 1
    Gosub PressKey
    key=key+1
    If (key>90)
        key=65
    EndIf 
    SetEnvironmentVar "Key",CStr(key)
EndWhile 
EndScript 
Sub Thread1
    For 10
        Gosub PressKey
    EndFor 
Return 
Sub PressKey
    key=GetEnvironmentVar("Key")
    KeyPress key,1
    Delay 200
Return