chk ur database if the values u entered are at correct
place/ its an error.

Simply checking the database will not solve the problem. It 
might be possible that the values stored are correctly but 
when there is an internal validation through the code then 
the code written is such that it is not able to do the 
validations at the code level instead of datbase level. 
This again in turn will result in failure

chk ur database if the values u entered are at correct
place/ its an error.

chk ur database if ur value are correct so chk the value 
case sensitive or not.

report the bug to development team because sometimes the 
developer made the mistake or the valid user id does not  
exist in your database table 


if you enable to enter better report it to development team 
or dicuses with Test team Lead or Developer about the 
particular funcationality

If you are not able to login after entering a Valid user 
id/Passwd then you will not go for any further 
testing.Becasuse here your sanity testing fails.A valid 
user id/Passwd means you are not making any mistake while 
typing the user id/Paswswd...This means you should return 
the build to dev team without performing any further 
testing steps

In the broad ways two reasons could be there

(1) code level validation
(2) data base connectively,

Data base connectively error generally does not appear on 
the user module in the website/applciation.
As far as case senstiveness is concern, it is already 
define that entering valid user name and password.

Small or Capital letters does not matter in case of 
Password generally

Do you chack 
first,caps lock on/off.
second,code validation.
third,gave the database path is correct or not.
fourth,do you redirect page is  other page or same page.

after guiving the valid username and password,check for the
vlaidation.Wheather validation is been called in onsubmit
button.