to make eazy to understand

1.   create mdi container form
                   |
                   | in the mdi container
                   |
2.       add Panel (set dock to fill) this will make panel fill up the whole
mdi container
                   |
                   | in panel
                   |
3.     add tabcontrol (set dock to fill) it will fillup the whole panel

from menu :
Private Sub ReplaceToolStripMenuItem_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles ReplaceToolStripMenuItem.Click

Dim m_oReplace As New findreplace(loc_openDocList, TabControl1)

m_oReplace.MdiParent = Me

m_oReplace.Show

(no error , but the form not showing out , I even try to set top most on the
child form but no use)