Nothing in that code shows you using a text file: and if you are, you probably shouldn't unless it's for something other than just transferring information from one form to another.
If what you are trying to do is select a date on Form2 and get it to affect what is shown on Form1 then that's pretty easy, but exactly how you do it depends on the relationship between the forms.
If Form1 creates the instance of Form2:
Transferring information between two forms, Part 2: Child to Parent[
^]
If Form2 creates the instance of Form1:
Transferring information between two forms, Part 1: Parent to Child[
^]
If both Form1 and Form2 are created by a different form (Form3):
Transferring information between two forms, Part 3: Child to Child[
^]
If that isn't what you are talking about, then you need to clarify your question and provide more detail!