VB Code to Call Userform in Userform

Greetings!

Hello, I wonder if what code should I use to call another userform inside a userform. It keeps prompting me an error when I tried to insert a userform.show in a click event. here is the example.

this is the code to call the main userform

Private Sub CommandButton4_Click()
    frmSRStat.Show
End Sub

then this userform will appear.

Attachment 146862

here is the code for this main userform

Private Sub cmdClose_Click()
    Unload Me
End Sub

Private Sub cmdSelect_Click()
Sheets("Group SR").Range("N1") = ComboBox1.Value
If ComboBox1.Value = "ALL STATUS" Then
Sheets("Group SR").Range("N1") = ""
End If
Unload Me
End Sub

Private Sub Image1_Click()
frmCalendar.Show
End Sub

Private Sub TextBox1_Change()
Calendar1.Value
End Sub

Private Sub UserForm_Initialize()
With ComboBox1
    .Value = "ALL STATUS"
    .AddItem "ALL STATUS"
    .AddItem "ACTIVATED-CONFIRMED"
    .AddItem "ACTIVATED-QA"
    .AddItem "ESCALATED NPSD SOC BRO"
    .AddItem "ESCALATED NPSD SOC BRO - PREMIUM"
    .AddItem "ESCALATED_NPSD_CRG"
    .AddItem "ESCALATED-KSP"
    .AddItem "FEEDBACK"
    .AddItem "FOR_DEPLOYMENT"
    .AddItem "FOR_RESCHEDULING"
    .AddItem "OPEN"
    .AddItem "SCHEDULED-RESCHEDULED"
End With
End Sub

then in escalation date field. i will click the small calendar image so that the second userform will appear. but upon clicking, it will prompt me an error that says object required.

Attachment 146861

i tried to insert the line frmCalendar.Show(name of the second userform) in Private Sub Image1_Click() event then the error now prompts. I don't know how to call the second userform inside the main userform.