Closing sub window from parent window

[Satya]

I have a web page(ASPX) that causes a new window(ASPX) to be created.
It looks
something like this:
StringBuilder scriptBlock = new StringBuilder();
scriptBlock.Append("<a
id='viewEBillDocumentLink' name='viewEBillDocumentLink' href='");

scriptBlock.Append(UrlConstants.ViewEBillDocUrl);
scriptBlock.Append("' target='_blank'></a>\n");

scriptBlock.Append("<script
language='javascript'>\n");
scriptBlock.Append("<!--\n");
scriptBlock.Append(" var link =
document.getElementById('viewEBillDocumentLink');\ n");
scriptBlock.Append(" link.click();\n");
scriptBlock.Append("\n");
scriptBlock.Append("// -->\n");
scriptBlock.Append("</script>\n");
Page.RegisterStartupScript("ViewEBillDocument",
scriptBlock.ToString());


The above code works fine but When the user eventually logs out of the
web application from the "main" browser window, I want to close the sub
window created above.
see if you can give me a any light on it.

Thanks,
Satya.