hello im trying to create a callback mechanism from two child windows to a parent window when the user clicks the display child 1 button in the parent for callback test window that window is hidden and the chilld 1 window is visible . when the usr clicks the the go back to parent button in the child 1 window the child one window is hidden and the parent for callback test window is visible . the same action occurs for the dsplay child 2 button and the child two window. the parent for callback test window must implement an interface that provides a callback method. this is what i have but im getting errors can you help me

Click here to open the child window

This is Child window

function CallParent() { alert(" Parent window Alert"); } opener.CallParent(); not window.opener.CallParent();

this is from java programming chapter 10 creating a callback mechanism