Other form textbox

I run my VB.NET program. The Startup form is the Form1. Form1 has a TextBox1 control.
Then I show the Form2. I put this code to change the Form1's TextBox1 Text.
Dim aForm As New Form1()
aForm.TextBox1.Text = "The quick brown fox"
But the Form1's TextBox1 display nothing.
Kindly help with this code?

Isn't this post repeated ?;)