I just want to remove checkout option form a particular form library not all form library or document library.I also want to have edit rights of Users.
You can checkout the article here on How to hide ECB menu: msdn.microsoft.com/en-us/library/cc768565.aspxBasically you would like to remove the link only under certain conditions then you can go the above mentioned route to “virtually” overwriting the core function.Follow the article "How to: Hide a menu Item in the ECB from SharePoint List Items"In your custom java script you can check for certain conditions (basically some condition to check the list name) and decide dynamically based on user role or item state what you want to show/hide.Another simple option that comes to my mind is using sharepoint security to that on that specific list i.e. break the permission inheritance and dont allow EDIT on that list for all the groups except for ADMIN group (admin group is just an example here). This way you will security trim the permission and user won't see that option on that specific list.