Access controls on a different form.

[taigon]

I've searched for resolutions to not being able to access controls on one form from another and I'm having some issues.

From a separate form, I use this code...

               frmMain.tab_BottomPanel_MDITabs.TabPages(Convert.ToInt32(this.Tag)).Tag = true;

But I get the object reference required error.

I've tried doing this on frmMain...

       public string tab_BottomPanel_MDITabs_Tag
        {
            get { return (string) this.tab_BottomPanel_MDITabs.Tag; }
            set { this.tab_BottomPanel_MDITabs.Tag = value; }
        }

but from the other form, even tab_BottomPanel_MDITabs_Tag doesn't show up in the list.

How do I access the controls on the main form? The reason for this is because the secondary form is loaded into the main form in an MDI tab control so I need to be able to access the controls on the main form.