Oracle Forms

Hi

In a form I have block A. Which contains two columns Old Value and New Value both are of varchar datatype. I want to compare Old Value and New Value character by character and display the characters which are there in New Value but not in Old Value in a different colour when this block is being called.
Example1 :Old Value : 13-Jul-2007
And New Value : 19-Jul-2007
I need the output to be display in this way - 19(in different clour)-Jul-2007. Only 9 should be in different colour.

Example2 :Old Value : - (No value Previously)
And New Value : SI DONE
So output to be display in this way New Value "SI DONE" should be in different colour.

Just to hightlight the users that this is change made instead of they manually compare field by field for the changes to take note..

Pls help me this is bit urgent. Help me to suggest any java related coding can help me or any plugins that we can call thru forms to do it.. Pls help.

Rishi