define worksheet question

I have the code below that deletes a row based on a textbox value in a userform.

i need to define the worksheet to = "PROJECTS" but somethings not right here:

   lastrow = Worksheets("PROJECTS").UsedRange.Rows.Count

probably a simple fix but i'm stuck on it. any help is appreciated. Thanks!

Private Sub deletejob_Click()

 Select Case MsgBox("ARE YOU SURE YOU WANT TO DELETE THIS PROJECT?", vbYesNo)
    Case vbYes
    
   Application.ScreenUpdating = False
   Application.Calculation = xlCalculationManual
   Dim lastrow As Long, r As Long
   lastrow = Worksheets("PROJECTS").UsedRange.Rows.Count
   For r = lastrow To 1 Step -1
      If UCase(Cells(r, 3).Value) = jobno Then Rows(r).Delete
   Next r
   Application.Calculation = xlCalculationAutomatic
   Application.ScreenUpdating = True
   
       Case vbNo

End Select
   
End Sub