Hi Asif,
I am really sorry for the delay of this reply. Please find my answers from your inquiries below.
Before when I clicked to create a new blog then a conventional Text editor opened where a user could edit a blog and insert the image. Now its different. A concept of Block is to be used where Block of any media can be used.
I am not sure if my colleague has changed something on your site before but I have change the default editor to use JCE editor from your backend > easyblog > settings > composer > composer editor,
http://screencast.com/t/LJ2by4uy .
I am not able to insert a new image because when I clicked the insert button then a conventional dialog box opened but insert button was hiding below.
This is actually a known issue when your pc screen resolution is small and causing some of the button to missing. To fix this you need to use a popup feature instead of iframe for your JCE editor. I've change the settings from your backend > JCE editor > editor profiles > features and layout > inline popups and it should displaying correctly now. Check my screenshot here,
http://screencast.com/t/cmlLDBoax .
Hope these help.