It´s important to mention that the script that generates the erros runs in the child window.

The child window is created in another client script in the parent window. The parent window script looks like this:

<script language="javascript">
	function AbrirCategorias()
	{
		win=window.open('WFShowCategories.aspx', null,'toolbar=0,directories=0,status=0,menubar=0,scrollbars=1,resizable=1,width=400,height=300');
		win.creator=self;
	}
</script>

Thanks,

Eugenio