Enable PRINT After Saving

Is it possible to add a piece of code with the below code.

There are two Buttons in my Work Sheet. One "SAVE" the other "PRINT". If PRINT button is clicked by mistake before clicking SAVE button, a Pop up message should say "SAVE DATA FIRST". If Data is saved then based on that I should be able to Click PRINT Button.

( Or )

Enable PRINT Button only after DATA is Saved

Sub saveit()
With Sheets(2)
r = .Range("B65536").End(xlUp).Row + 1
InvN = Cells(15, 4).Text

'Clicking the "SAVE" button Without entering datas in the rest of the Fields,
'ie., in C18, C20, C22 and C24 should NOT save the Current Invoice number
'with the rest of the details in the next sheet. A pop up should say that
'"Fill all Fields" when trying to hit the Save button if a Field is blank.

If Range("c18") = "" Or Range("c20") = "" Or Range("c20") = "" Or Range("c22") = "" Or

Range("c24") = "" Then
MsgBox "Please fill all required fields", vbCritical, "Missing data"

Exit Sub
End If