VCenter ESX V5.5 Login Error

If you were use VMware vCenter Server V4 and now you are starting to use V5.5 vCenter server to manage newer VMWare ESX Vsphere, first you will get the error when login, it will say incorrect username or password, because for new vCenter the format for inserting your username is different from V4 vCenter, in the new vCenter for local username you have to use format: user@vsphere.local