passing control from control to the worksheet

[warehouseman]

I have a command button

Private Sub ResetALL_Click()
     me.stopone.value=nul
     me.stopone.visible=false
     Worksheets("Calculator").calculate
End Sub

stopone is a drop down menu that looks up information for a table on a another sheet.

Based on the stopone value now being nul another cell (A11) on the sheet should go blank but it retains the previous value from stopone. As soon as I click on the worksheet itself A11 goes blank. I've tried adding the line "Worksheets("Calculator").calculate to the code but it does nothing. It only recalculates when I click on the worksheet. What am I doing wrong and how do I do it correctly?