Can't debug when trying attach to process w3wp.exe

Hi,
I am attaching to my asp.net application via the process, w3wp.exe. After I clicked on the Attach button, i added breakpoints to the login.aspx page. In the iExplorer, I typed in the url for the login.aspx page. The login page came up but the breakpoint was not caught. I detached and reattached but I been unsuccessful in trying to catch the break point to debug.
FIGURE IT OUT.... needs to be in debug mode..