Hi,
we will write script in 2ways.
1.by using properties collections
2.by using Description.create
example:
 Dialog("text:=login).winedit
("attachedtext:=username").set "xxxx"
 dialog("text:=login").winedit
("attachedtext:=password").set "yyyy"
 Dialog("text:=login").winbutton("text:=ok").click

Hi there, 

I was with a concept that the application technology is 
independent of QTP script. (I mean the Script will always 
be a VB based in QTP. And for Java based application we 
need to have a JAVA addin)

Please correct me if I'm wrong.

Hi i think that the QTP script will be the same. we use the
VB  script in QTP. and the format would be the same.. The
QTp will identify the objects with obj Properties.. or we
will do discriptive programming..

I think  Vijayendra Reddy is correct. Its a question to the
script for Windows Application...

Correct if I am Wrong

VBScript is scripting language which is used by QTP. QTP
supports no.of environments. Initially we have to check
particular addin and enter. QTP prepares methods for that
environment in background and it identify the object and
generates steps with that methods. 

for Java application, we have to install java addin and
check java addin before we start scripting.

QTP will record script in the form of 

javawindow("Calculator").javabutton("1").click
javawindow("Calculator").javabutton("2").click
javawindow("Calculator").javabutton("+").click
.
.
.
.

if you wanna write scripts in descriptive you can go like this
javawindow("windowname:=Calculator").javabutton("text:=1").click
javawindow("windowname:=Calculator").javabutton("text:=2").click
.
.
.

you can use collection object 

dim window
set window=description.create()
window("title").value=Calculator

javawindow("window").javabutton("text:=1").click
javawindow("window").javabutton("text:=2").click
.
.
.
.

Whether it may be 2 tier/3tier/n tier architecture....

nothing will be different, the script would be in VBScript.
according to the environment,application the methods will
change...