非常郁闷! 请各位高手帮忙
运行下列代码时时老是提示"密码错误"



string ls_uname,ls_pwd1,ls_pwd2,ls_sno,ls_s1
ls_uname=sle_uname.text
ls_pwd1=sle_pwd.text
select sno
into :ls_sno
from t_student
where t_student.sno=:ls_uname;
if sle_uname.text="" or sle_pwd.text="" then
messagebox("提示","用户名或密码不能为空,请输入用户名或密码！")
sle_uname.text=""
sle_pwd.text=""
return
end if
select password
into :ls_pwd2
from t_student
where t_student.sno = :ls_uname ;
if ls_pwd1 =ls_pwd2 then
open(w_main)

else
messagebox("错误","用户名或密码错误，请重新输入!")
sle_pwd.text=""
return
end if

高手们，快啊

各位大侠，赶紧的