var ie4=document.all&&!document.getElementById;
var DOM2=document.getElementById;

function get_span ( span_id )
{
    span = null;
	if (DOM2)		span = document.getElementById ( span_id );   
	else if (ie4) 	document.all.span_id;
	return ( span );	
}

function show_span ( span_id )
{
	span = get_span ( span_id );
	if ( span )		span.style.display="block";
}

function hide_span ( span_id )
{
	span = get_span ( span_id );
	if ( span )		span.style.display="none";
}

function add_span_text ( span_id, text )
{
	span = get_span ( span_id );
	if ( span )		span.innerHTML += text;
}

function set_span_text ( span_id, text )
{
	span = get_span ( span_id );
	if ( span )		span.innerHTML = text;
}

function switch_spans ( span2show, span2hide )
{
	hide_span ( span2hide );
	show_span ( span2show );
}

function set_span_class ( span_id, classname )
{
	span = get_span ( span_id );
	if ( span )		span.className = classname;
}

function get_span_class ( span_id )
{
	var classname = "";
	span = get_span ( span_id );
	if ( span )		classname = span.className;
	return ( classname );
}

function expand ( item_id )
{
	set_span_class ( item_id, "expanded" );
}

function collapse ( item_id )
{
	set_span_class ( item_id, "collapsed" );
}

function auto_expand ( item_id, span_id )
{
	var classname = get_span_class ( item_id );
	if ( classname == "expanded" )	collapse ( item_id );
	else							expand ( item_id );
}

function is_visible ( span_id )
{
	retval = false;
	span = get_span ( span_id );
	if ( span )  retval = ( span.style.display != "none" );
	return ( retval );
}