if there is a pop up message then u just add it to ur 
object repository & make the qtp to click on the ok 
button..you make this as a function & validate ur login 
page as  many time as you wantn call ur function

Hi Friend

           You can go through the "Recovery Scenario" for
this kind of problem. Steps are..in QTP 9.2

Resources-> Recovery Scenario Manager-> click on first image
that is with right side of "Scenarios"(only the enabled
image)text-> read the content and "Next"-> these are the
condition wherever we use Recovery Scenarios select one of
them according wat type of error you have(pop up
window)->"Next"->Click on "Hand" pointer and capture the
popup window and "Next"->"Next"->Select the event you want
to perform "next"->"Next"-> From Recovery operation window
un select the check box and "next"-> "next->"next"-> Write
some description or not(optional)->"next"-"Finish"->"Save"
in your destination.

         Now you can use that in your script. 

Have a look(softestonline-neeraj043.blogspot.com)

Suppose the same pop window generated while running test 
case and while recording it was not generated & values were 
properly inserted. What procedure is require please explain 
with details? 

alkaa.dugaal@gmail.com

Dear Alkaa,
     i am just describing the scenario.
1.Open gmail/yahoo or any site.
2.Enter your valid userid and invalid password.
3.We can see a pop-up window with a message "Please enter
the correct password or Password invalid "  
even i know the right scenario
4.But i just wanna know how to capture the pop-up window.

Thanks,
Sasmita

Identify this pop up and buttons on this pop up as an object
and add it in repository. Now use MouseMove function to move
mouse pointer over this pop up and click on "Yes" or "No"
button according to your requirement.

Note:- I am assuming that pop up is a type of window object

Hi Sashmita,

Thank you for your efforts, but my concern is just opposite 
of the given question. We know that entering invalid info 
will obviously invoke a pop up. but in my case when I am 
inserting correct/valid information in all fields while 
recording (www.propertiesthisweek.com-->New Registration 
Now) and during run time, it generates pop "Please select 
the profile" for Profile type. Now I hope you it would be 
clear to you.

Hi all,
I have read all the answers.
By using recovery scenario we can just click ok button on 
the pop up window.
If we want to enter in to the application ,I think even 
recovery wont help it.
If the question is about validation then validate the 
username and password by if else statement for Pop up 
existence.
If not the data must be correct

When ever u got the popup window you can make it that 
ststement as optional.When ever you make it optional if the 
popupwindow appears it will take care other wise move to 
next step.