多线程 创建包含线程的类出错！

不需要创建类
imports system.threading
sub1()
do something here
thead.sleep(100)
end sub

sub2()
do something here
thead.sleep(100)
end sub

sub()
dim td1 as new thread(adress of sub1)
dim td2 as new thread(adress of sub2)
td1.start
td2.start
end sub

手写的,望能看懂.