How to change attribute value of one class from second class

Hi all,

I have a requirement, in which i need to do this. Let me cler by this example: I have two files, A.java & B.java, A file contains one textfield, txt. I need to set the value of txt as null, but from B file. Both of these files are in same package Miniproject of c drive.
Please suggest me the appropriate. Thanks in advance.

B does not extend A, right ? You could have a public setter method in A, which sets the textfield to null.