Hi Sowmya,
For scripting, select the field from left hierarchy tree, now on the script editor select the dropdown where it says "events with scripts"
1) see the dropdown "Events With scripts" and if you have a * beside it mean there is a script in one of the events else no script yet on this field.
2) The dropdown will enable all events possible on the selected component.
3) if there is a * beside an event it mean there is some code in it.
Well this is just by looking at the screen shot, and I don't see any reason of freeze.
Cheers,
Sai