call a function from Form to another form using C#.net

Hi,
Project has a 3 Forms.that is Form1,Form2,Form3.One button is in the Each form.One Function is in the Form that is called Message(). I just call that function from Form3.
But It is not worked.

Form1
private void button1_Click(object sender, EventArgs e)
{
Form2 frm = new Form2();
frm.Show();
}


Function
public void message()
{
pictureBox1.ImageLocation = @"C:\Documents and Settings\User\My Documents\My Pictures\index.JPEG";
}


Form2
private void button1_Click(object sender, EventArgs e)
{
this.Close();
Form3 frm = new Form3();
frm.Show();

}
Form3
Declaration
Form1 frm = new Form1;

private void button1_Click(object sender, EventArgs e)
{

frm.message();
this.Close();
}


But it is not worked.Please help me.why?I upload a picture in the Picture Box. how to solve this issue?Please do needful...