Error page when i host in this server

I am getting this error Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.

Source Error:

Line 16:
Line 17:
Line 18:
Line 19:
Line 20:

Source File: C:\MemberSites\MemberSites_AspSpider_Info\ifadesigners\webroot\jobportal\web.config Line: 18

try to solve this error as soon as possible.