VB中同一工程不同窗体如何让动态数组共用？

我想在窗体一中输入数据形成数组，然后在窗体二中调用这个数组，想在模块中定义这个数组让它共用，但是为什么会显示错误“下标越界”？比如下例：
窗体一：
Private Sub Command1_Click()
Static cishu As Integer
cishu = cishu + 1
a(cishu) = Text1.Text
x = cishu
End Sub

窗体二：Private Sub Command1_Click()
For x = 1 To cishu
Print a(x)
Next
End Sub

模块一：
Public a() As Integer

（大神求解！！拜托拜托）

窗体一：
Private Sub Command1_Click()
redim preserve a(cishu)
a(cishu) = Text1.Text
cishu = cishu + 1
x = cishu
End Sub

窗体二：Private Sub Command1_Click()
For x = lbound(a) To ubound(a)
Print a(x)
Next
End Sub

模块一：
Public a() As Integer
Public cishu As Integer

form1： dim a() private sub form_load() redim a(9) a(1) = "速度": a(2) = 1234 form2.show end sub public property get a_val(index as long) a_val = a(index) end property public property let a_val(index as long, byval vnewvalue) a(index) = vnewvalue end property form2： private sub command1_click() msgbox form1.a_val(1) form1.a_val(1) = 5 end sub