I have .aspx page that page inserts the data to the database on a button click. But when i press the button it is going right. i m getting the Successfully message as \" success
The refresh will re-submit the form you posted last time when you clicked the button.
Usually, when you refresh a page you think of GETing the page again, or doing an HTTP GET, but since the last thing you did was a POST (when you clicked the submit button) the browser will perform the post again to attempt to invoke the same response.
I suggest using the Post/Redirect/Get pattern as suggested by Jorn Schou-Rode.
This article also seems relevant. http://aspalliance.com/687_Preventing_Duplicate_Record_Insertion_on_Page_Refresh