myFrm = New frm_AddBookType
        myFrm.mdiparent = Me
        myFrm.show()

frm_AddBookType为新增加的窗体,本人刚接触 ,不知 myFrm 应该怎样定义,向大家请教,谢谢了

谢谢你的回答,我的意思是要将窗体的值赋给myFrm 的

    Dim myFrm XXXXX,就是不知道这个值是什么类型


    Private Sub MenuItem11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MenuItem11.Click
        myFrm = New frm_AddBookType
        myFrm.mdiparent = Me
        myFrm.show()
    End Sub

Private Sub MenuItem12_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MenuItem12.Click
        myFrm = New frm_AddNewBookCode
        myFrm.mdiparent = Me
        myFrm.show()
    End Sub