generally login screen will have the titel bar,user id,text 
box,password .,ok button, cancel button,help button

 THE CONDITIONS R 
IT SHOULD START WEITH ALPHANUMERIC IN LOWERCASE FROM 4 TO 
16 CHRACTERS LONG,PASSWORD ALLOWS ALPHABETS IN LOWER CASE
OR NUMBERS.

TASTE CASE 1 

SUCCESSFUL ENTRY OF USER ID
BVA
MIN=4CHAR===== PASS           VALID     INVALID
MAX=16 CHAR====PASS           a to z     A TO Z
MIN-1=FAIL                    0 TO 9
MAX+1=FAIL
MIN+1=PASS
MAX-1=PASS

TEST CASE 2
SUCCESSFUL ENTRY OF PASSWORD

BVA
MIN= 4CHAR====PASS            VALID    INVALID
MAX= 8CHAR===PASS             a to z   A TO Z
MIN-1=FAIL                    0 TO 9
MAX+1==FAIL
MIN+1=PASS
MAX-1=PASS

TEST CASE 3

SUCCESSFUL LOGIN OPERATION

UID       PW           CRITERIA

VALID     INVALID       PASS
INVALID   VALID        FAIL
VALID     INVALID      FAIL 
INVALID   INVALID      FAIL
VALID     BLANK        FAIL
BLANK     VALID        FAIL


ANY MORE DOUBTS PLZ ASK ME 

N.VENKATRAMAN 
TESTING ENGINEER
HYD 

we can do Negative testing in order to check Error handling
not onlu the aboue general checkings..

1st one is not complete. We have to check security level 
also.if it is web bacsed - after log in to application we 
need to go back and check wheather copy paste of browser 
address is working.

We Need to get the requirements first, & based on the 
requirements we need to test the login interface.

Again its tht simple , i check for boundary conditions , 
tab movement ...giving inputs for execution such as 
alphabets ,numericals , alphanumericals , 
total number of test cases for this is 20

Hi,
I would like to add one more test case regarding security
testing.

Pls check that user is not able to copy paste the password
from provided text box to word document/notepad

First we go for GUI and the functionality by writing 
Postive and Negatvie testcases

GUI testcases
1. Check for the availabiliyt of login sreen.
2. Check for the availability of user name field.
3. Check for the availability of Password field.
4. Check for the availability of Signin and ok  button.
and we can write more testcases depending up on the  
requirements...
POSITIVE testcases.
1. Invoke the Login screen.
2. Enter valid user name and valid password.
3. click on signin or ok button.
To write a positve testcase the tester should be in 
Positive mindset.
NEGATIVE testcases..
1. Invoke the Login screen.
2. Enter invalid user name and invalid Password.
3. Click on signin or ok button.
in this case u have to think in both ways to match ur 
testcase with the requirements and to match with the 
expected value to the actual value.

guess u understood 

any douts u can mail me to ajay.thomala@gamil.com