SharePoint - Newform.aspx in list

I have a list called "Sales" which has newform.aspx and i made this page as pop-up dialog using javascript.Now when i hit save button ,it should take me to thank you page .but i am getting that thank-you.aspx in pop dialog box. how to redirect it to completey new page but not in pop-dialog box.??

Try this code:

Response.Write("<script>window.open('http://www.yoursite.com/thank-you.aspx','_blank');</script>"); 

do i have to put this code in html editor box or in code-behind of newform.aspx

code-behind