User Form look at 2 Txt Boxes for entry but needs only one completed or a MSG will display

Hi There...

I have the following code (See below) that warns the User to input the required data into the relevant fields. If he tries to submit the data with an empty field then a message is displayed. My problem here is that the statement need to look at both the fields but, requires that only the one must be completed. However the field completed can be either "Textbox_ReclaimedSand15sec" or "Textbox_ReclaimedSand30sec".

If Trim(Me.Textbox_ReclaimedSand15sec.Value) = "" Then
Me.Textbox_ReclaimedSand15sec.SetFocus
MsgBox "Please enter Reclaimed Sand Weight", vbExclamation, "Movements"
Exit Sub
End If

If Trim(Me.Textbox_ReclaimedSand30sec.Value) = "" Then
Me.Textbox_ReclaimedSand30sec.SetFocus
MsgBox "Please enter Reclaimed Sand Weight", vbExclamation, "Movements"
Exit Sub
End If

Does anyone know what code I need to add to above?