How to check multiple text box using java script
I am newer in asp.net 2010, I have a page which contains 10 text fields. every fields should be checked empty text or null value. but I want to use java script function which checks every text field. in that case I want to write function like 'CheckEmptyText' using js file and want to call from code behind language because i don't want to call from body in .aspx file. show how to possible please give me a hints or sample project so that I can followup the way.
In addition to that I have another question that is it necessary to check validation from both side client and server. and what is difference between client and server side validation checking.
Please assist me.