how to create on blur validation in asp.net MVC

Hi frnds,

       Im working on a simple asp.net MVC.

My view consist of name ,no and some fields with validation messages(char should not exceed  30,10 digit mobile like that).

The problem is validation message is printed only when i post a request.What should i do to display a validation error as soon as I move from one field to another.

         Please help me solve the problem.thanks in advance.