Thanks for your help,but sorry i am unable to understand the example code given by you,I am giving you the details what exactly i wants to do with javascript.

I have created a module,in this modules i have placed a datagrid/radgrid in this modules, i have placed 3 asp buttons and 1asp textbox.What i am doing is depending upon the button ,grid is filled with data.Textbox is used for search operation for datagrid.i have put a word in this textbox and after that click on search buttons will gives us the required result in datagrid.

Here comes my javascript requirement ,i wants when user click on search button if the textbox is left empty then an error message should comes like"enter search text",rather i can also do this by putting required field validator in my module,but i wants to check this validation with java script.

Please help me by providing proper guidence how we can resolve this problem ,also provide me the code that accomplish my result.

Thanks in advance