Problems with grid saveChanges event

[M]

I'm intending to use the Grid's saveChanges event to perform some custom validation and prevent the record being saved if necessary.

I've had a look through these forums and it seems I should be able to prevent the save using:
   saveChanges: function(e) { 
e.preventDefault();
   }

This isn't working. All records are being saved.

Can somebody please explain what the saveChanges event is for, when it is called and how it should be used. The documentation is very sparse.

Thanks.

[Scott Marx]

Did you ever get an answer?

[Scott Marx]

I found the solution. The saveChanges: must be after the tool:

toolbar: ["create", "save", "cancel"],
saveChanges: function (e) {
handleSaveChanges(e, this);
},