Using Expect & TCL/TK i want to login to my application;

[HIMAs]

OS:WINDOWS
Using Expect & TCL/TK i want to login to my application:
But my appl'n got a character User Interface Which conatins one boxframe with "USER" and "PASSWORD" field
Now i want to login to go to next screeen.but i can reach there by
" set exit_status 1
set user USER
puts $user
set pass PASSWORD
puts $pass
cd $env(HOME)
set id bobby #this my application's exe
send [exec $id] #i am invoking my application from propmt
send "$user\t$pass\r" #i am sending user & password
expect "Exit System" #i am expecting mySIGN

My logon screen is :[dos application]

----------------------------------------------------
USERNAME [ ]
PASSWORD [ ]
Exit System
----------------------------------------------------

Ok well my problem is to send USERname and Password simoultaneously.and then press enter to go to next screen
i used command: send "$user\t$pass\r" but what happens is it's just giving both id & password in some place.not in the designated columns:SO Logon is not happening

How to do that so that i can go to next screen:
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HAI WELCOME
opt[]
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Looking fwd for you valuable suggestion