/*  bbbscroll, version 1.2
 *  (c) 2007 Marco Weesjes <mwe@bisc.nl>
 *
 *  20070314 mwe 1.1 aanvulling.
 *  20070323 mwe 1.2 aanvulling.
 *
 *<componentinfo>Product MVrenegoor</componentinfo>
 *<versioninfo>4.00 (2010-09-28)</versioninfo>'
 *<changeinfo> 4.00 (2010-09-28);tvl;</change> 
/*--------------------------------------------------------------------------*/

var elemM,elemC ;
var top = 0 ;
var scrollheight = 0 ;
var actualheight = 0 ;
var offset       = 0 ;

function initieer(divM,divC,divP)
{
	elemM = $(divM) ;	// master (view area)
	elemC = $(divC) ;	// child (content area)
	elemP = $(divP) ;	// pijltjes

	ah = parseInt(elemC.offsetHeight) ;
	sh = parseInt(elemM.offsetHeight) ;
	
	if ( ah >= sh )
	{
		elemP.style.visibility = "visible" ;
	}
	else
	{
		elemP.style.visibility = "hidden" ;
	}
}
	

function scroll(dir)
{
	if ( scrollheight == 0 )
	{
		actualheight = parseInt(elemC.offsetHeight) ;
		scrollheight = elemM.offsetHeight ;
		if ( offset == 0 )
		{
			offset  = scrollheight ;
		}
	}

	y = offset * ( dir == 'up' ? (+1) : (-1) ) ;
	
	if ( dir == 'top' ) { top = 0 ; y = 0 ; }
	
	if ( (top+y) > 0 ) { top = 0 ; y = 0 ; }
	sh = ( offset == 1 ? scrollheight : 0 ) ;
	if ( (top+y) < (actualheight-sh)*(-1))
	{} else { top += y ; elemC.style.top = top + "px" ; }
}

var lefttime;
function initScroll(dir)
{
	offset = 1 ;
	lefttime = setInterval("scroll('"+dir+"')",20) ;
}
function stopScroll()
{
	offset = 0 ;
	clearInterval(lefttime);
}