excel - Vba UserForm combobox items don't apear till i click on the userform -

i have command button, when click it, shows customized userform contains combobox items taken sheet cells. user suppose press command userform appears, needs select 1 item list, item sheet name in different workbook, accordingly import data sheet. facing problem: when userform appears, click on combobox shows no items, if click once on userform check combobox again shows items correctly, if click again on userform, combobox items doulbled! if selected item works perfectly. want achieve is: want combobox show items directly without clicking on userform. code this:

in userform:

private sub userform_click()    dim mlf workbook  dim adad long  dim mada string  dim lastrow long  set mlf = activeworkbooklastrow = sheet3.cells(rows.count, 1).end(xlup).row  adad = 1 lastrow  mada = sheet3.cells(adad, 1)  combobox1          .additem mada  end  next      end sub   private sub cmdokay_click()   'verify item selected  if me.combobox1.boundvalue = vbnullstring      msgbox "you did not choose item!", vbokonly      exit sub  else      msgbox "you have selected " & me.combobox1.boundvalue, vbokonly      sheet3.cells(1, 2) = me.combobox1.boundvalue   end if     unload me   end sub 

in commandbutton

dim testbook workbook  set testbook = thisworkbook  set database = workbooks.open(filename:=mypath & myfile)  testbook.worksheets("sheet4").range("a1:b5").clear  userform1 .caption = "settings of test" end  dim lo integer  lo = 1 database.sheets.count       testbook.sheets("sheet4").cells(lo, 1) = database.worksheets(lo).name  next  userform1.show 

that because telling on click event.

change

private sub userform_click() 

to

private sub userform_initialize() 

once change this, combobox issue go away.