I am trying to run this following code behind the ok button of my login screen. But it's not releasing properly. What am i missin?

oVar.UserIdText = allt(ThisForm.UserIdTxt.Value)
oVar.UserPwdText = allt(ThisForm.UserPwdTxt.value)

sele lc_users
go top
locate for (allt(upper(user_Id)) == allt(upper(oVar.UserIdText)) and allt(upper(user_Pass)) == allt(upper(oVar.Userpwdtext)))

IF FOUND()
** OPEN UP TAMA MENU AND LOGO SCREEN **
do TAMA.mpr
DO FORM LOGO.SCX
thisform.release()
ELSE
&&Invalid User Id and/or Password
oApp.DisplayMessage('10')

ThisForm.UserIdTxt.Value = ""
ThisForm.UserPwdTxt.value = ""
oVar.UserIdText = allt(ThisForm.UserIdTxt.Value)
oVar.UserPwdText = allt(ThisForm.UserPwdTxt.value)
ThisForm.UserIdTxt.setfocus()
thisform.refresh()
return
ENDIF