Set all other fields read only when state is cancelled

[moni170]

I'm trying to set all fields read only when my state on incident form changes to canceled!!

Here's the code i've written and i'm currently using utah version but this code isn't working. Is there any possibility that getEditablefields() function doesn't work anymore?

If there's any other solution, do let me acknowledge.

That'll will be a great help.

[desaiakash0]

When I used this script my instance getting slow  and went in hung state 
can you explain why this happnes.

[PravinHirekudi]

function onChange(control, oldValue, newValue, isLoading, isTemplate) {
   if (isLoading || newValue === '') {
      return;
   }
   if(newValue == '8'){
	var field = g_form.getEditableFields();
	for (var i=0;i<field.length;i++){
		g_form.setReadOnly(field[i],true);
	}
   }
   
}