All the below steps are working fine. But the problem is parent screen gets refreshed though the field validation fails(showing alert box).
 Parent window with add button
 Click 'Add' button
 Opens 'Add' Popup window with some fields and 'Save' button
 User enter values and click 'Save' button
 Validate the fields using struts validator framework(client side validation)
 Once validation success corresponding action needs to be executed & update the data in database
 Parent screen needs to be refreshed without closing the popup screen
If more clarifications are required, please revert back.