I designed as aspx dotnet website,ran on my system working properly but when I host it will display an error message below;
I need help urgently please:

Runtime Error
Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.

Details: To enable the details of this specific error message to be viewable on remote machines, please create a customErrors tag within a "web.config" configuration file located in the root directory of the current web application. This customErrors tag should then have its "mode" attribute set to "Off".

Web.Config Configuration File

configuration
system.web
customErrors mode="Off"
system.web
configuration

Notes: The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's customErrors configuration tag to point to a custom error page URL.

Web.Config Configuration File

configuration
system.web
customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"
system.web
configuration

What can I do to avert this?