Change a button's icon from a different frame

Forgotten my old username and password! :| I also tried to search on the forums for this and it's of little help.

Anyhow, I am making a paint program for my project at uni. I have a panel (in a frame) that has buttons on them. Each button loads up a frame.
I made each frame has their own set of buttons so...
Tools button will open ToolsFrame which contains Pencil button, Paintbrush, Circle, etc.

What I want to do is change the Tools button icon so that it reflects whatever the user chose in the ToolsFrame. Is there a simple way of doing this?

e.g.
I set the buttons up like...
JButton toolsBtn = new JButton("images/tools.JPG");

Pressing toolsBtn will make a new ToolsFrame object:
public void actionPerformed(ActionEvent e)
{
if("tools".equals(e.getActionCommand()))
{
tools = new ToolsFrame();
tools.show();
tools.setLocationRelativeTo(this);
tools.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
}
ToolsFrame is a whole class extending JFrame and implementing ActionListener. The buttons in ToolsFrame are setup just like the toolsBtn above:
JButton paintbrushBtn = new JButton("images/paintbrush.JPG");

Pressing any button in ToolsFrame will close the window.

Did you try the method setIcon() of JButton? this will set your icon to whatever you want whereever you want

ah right...lol. I wondered why it didn't work - i didn't put in any event listeners to actually invoke setIcon(). that was simpler than expected tbh. lol.