material required for message box

hi friends,

i need the material on message box.

that means i am doing validation on the various fields

like on the numeric field the user should not enter more 100.,

if the email entered is not correct some message should be displayed,

if he click on the particular check box some message should be displayed.like that i have to do some validations.

under which event the respective code should we write..

Edited by: SRIPATHI RANJITH on Aug 12, 2008 6:11 AM