Disable a sub grid

Hi,

    I have three questions,

1. When a record is deactivated, all controls are read only by default, so when you click on sub grid it, "add new" and "add existing button" of that sub grid are disabled. But we need to have disable those buttons in an active record. I know that document.getelementbyId() is not supported. Is there any supported alternative?
2. I want to refresh a form. I used Window.location.reload(true), but it is considered as an issue when i ran Microsoft Custom Validation Tool.  Is there any supported alternative?
3. When i ran Microsoft Custom Validation Tool, it raised many issues in JSON and Jquery libraries files (the JS source code of the libraries). Is that normal