Using Child Functions from a Parent form

[RobAMacAF]

I am using:
private void New_Click(object sender, EventArgs e)
{
f = new ChildForm();
f.MdiParent = this;
f.Text = "Form - " + this.MdiChildren.Length.ToString();
f.frm1=this;
f.Show();
}

to create child windows in a MDI container. In the child form I have:

public void eraseWindow()
{
foreach (DictionaryEntry myDE in roomList)
{
Rooms foundRoom = (Rooms)roomList[Convert.ToInt32(myDE.Key)];
if (foundRoom.ShowRoom)
{
foundRoom.ShowRoom=false;
foundRoom.ThisButton.Hide();
}
}
MessageBox.Show(Convert.ToString(roomList.Count));
}

This just loops through the buttons on the child form and hides them all...

In the main form I want it that when you click on the menu EDIT, then CLEAR FORM it will run this function for the child form. Is there any way to do that?

I have tried (in the parentform)

void DeleteRoomToolStripMenuItemClick(object sender, EventArgs e)
{
f.eraseWindow();
f.redrawWindow();
}

f is the name of the childForm. But I get an error on it.

Any and all help would be GREAT!
Thanks in advance.

Rob

[RobAMacAF]

I was trying to get creative and even tried this in the parent form instead of it being in the child form (with a few modifications)

void DeleteRoomToolStripMenuItemClick(object sender, EventArgs e)
{
foreach (DictionaryEntry myDE in f.RoomList)
{
Rooms foundRoom = (Rooms)f.RoomList[Convert.ToInt32(myDE.Key)];
if (foundRoom.ShowRoom)
{
foundRoom.ShowRoom=false;
foundRoom.ThisButton.Hide();
}
}
MessageBox.Show(Convert.ToString(f.RoomList.Count) );
}

I am trying to pull the info from the child form but end up getting
Object reference not set to an instance of an object