question : Variable problem between forms

i use a public variable in form 1
and i try to use the same variable in form 2 and it don't let me do it
when i use the same new variable on form2 its act like new variable
form1:

Public Class Form1
    Public myexel As New Excel.Application

form2:

Public Class Form2
    Public myexel As New Excel.Application

i want to use the same one like i form1
what should i do?
thanks for help