Hi Chayan,
You can define your own sorting function on each column with the DataGridColumn.sortCompareFunction property. Set it to a function with the following signature:
mySortCompareFunction(obj1:Object, obj2:Object):int
The function should return a value based on the comparison of the objects:
* -1 if obj1 should appear before obj2 in ascending order.
* 0 if obj1 = obj2.
* 1 if obj1 should appear after obj2 in ascending order.
Jon Emerson
http://www.jonemerson.net/