Admin wants to login as another user

Hi All..

 

we have two types of users i.e 1.) users 2.) Admin

user was logged in to the website and he got the home page.. suppose user have facing some issues on his home page or some any other page .. he will inform to admin like.. boss i have some issue on my page can you please check it ... and then Admin will logged in with his credentials .. and Admin will check the whether user will exist or not , if user will exist ..admin wants to see the user page .. while admin will open user page .. user wants to get message like (Admin was logged in)