function get_fileinfo(item)
{
	var info = new Array(3);
	var i = item.lastIndexOf(":");
	info[0] = item.substr(0,i);
	var s = item.substr(i+1);
	i = s.lastIndexOf("x");
	info[1] = s.substr(0,i);
	info[2] = s.substr(i+1);
	return info;
}

function get_content_idx(idx, cntId)
{
	var info = get_fileinfo(arImg[idx]);
	var sFilename = info[0];
	var x = info[1];
	var y = info[2];
	if ((x > r) || (y > r))
	{
		var scale = x / y;
		if (scale < 1)
		{
			x = Math.round(r * scale);
			y = r;
		}
		else
		{
			x = r;
			y = Math.round(r / scale);
		}
	}
	var content = '<a href="javascript:set_selection_cnt(' + cntId + ')"><img src="./' 
		+ curDir + '/' + sFilename + '" width="' + x + '" height="' + y + '" alt="' + sFilename + '" border="0"></a>';
	document.getElementById('content' + cntId).innerHTML = content;
	content = (idx+1) + "/" + arImg.length;
	document.getElementById('num' + cntId).innerHTML = content;
}

function get_content(n)
{
	anfIdx = anfIdx + n;
	endIdx = anfIdx + 4;
	if (anfIdx < 0)
	{
		get_content_anf();
		return;
	}
	if (endIdx > arImg.length-1)
	{
		get_content_end();
		return;
	}
	get_content_idx(anfIdx+0, 1);	
	get_content_idx(anfIdx+1, 2);	
	get_content_idx(anfIdx+2, 3);	
	get_content_idx(anfIdx+3, 4);	
	get_content_idx(anfIdx+4, 5);	
	set_selection_cnt(selected_col);
}

function get_content_anf()
{
	anfIdx = 0;
	endIdx = 4;
	get_content_idx(anfIdx+0, 1);	
	get_content_idx(anfIdx+1, 2);	
	get_content_idx(anfIdx+2, 3);	
	get_content_idx(anfIdx+3, 4);	
	get_content_idx(anfIdx+4, 5);
	set_selection_cnt(1);
}

function get_content_end()
{
	anfIdx = arImg.length-1 - 4;
	endIdx = anfIdx + 4;
	get_content_idx(anfIdx+0, 1);	
	get_content_idx(anfIdx+1, 2);	
	get_content_idx(anfIdx+2, 3);	
	get_content_idx(anfIdx+3, 4);	
	get_content_idx(anfIdx+4, 5);
	set_selection_cnt(selected_col);
	set_selection_cnt(5);
}

function hide_selection_cnt(cntId)
{
	if ((cntId >= 1) && (cntId <= 5))
	{
		document.getElementById('c' + cntId).style.backgroundColor = "";
		document.getElementById('c' + cntId).style.borderBottom = ""
		document.getElementById('c' + cntId).style.borderLeft = "";
		document.getElementById('c' + cntId).style.borderRight = "";
		document.getElementById('c' + cntId).style.borderTop = "";	
	}
}

function set_selection_cnt(cntId)
{
	if ((cntId < 1) || (cntId > 5))
	{
		return;
	}
	hide_selection_cnt(selected_col);
	selected_col = cntId;
	var borderstyle = "solid black 2px";
	document.getElementById('c' + cntId).style.backgroundColor = "saddlebrown";
	document.getElementById('c' + cntId).style.borderBottom = borderstyle;
	document.getElementById('c' + cntId).style.borderLeft = borderstyle;
	document.getElementById('c' + cntId).style.borderRight = borderstyle;
	document.getElementById('c' + cntId).style.borderTop = borderstyle;
	var idx = anfIdx + cntId - 1;
	var fileinfo = get_fileinfo(arImg[idx]);
	var sFilename = fileinfo[0];
	var x = fileinfo[1];
	var y = fileinfo[2];
	var r = 600;
	if ((x > r) || (y > r))
	{
		var scale = x / y;
		if (scale < 1)
		{
			x = Math.round(r * scale);
			y = r;
		}
		else
		{
			x = r;
			y = Math.round(r / scale);
		}
	}
	var path = './' + curDir + '/' + sFilename;
	var content = '<img src="' + path + '" width="' + x + '" height="' + y + '" alt="' + sFilename;
	if ((fileinfo[1] > r) || (fileinfo[2] > r))
	{
		 content = '<a href="' + path + '" target="_blank">' + content + '" border="3" style="border-color:red"></a>';
	}
	else
	{
		 content = content + '" border="0">';
	}
	document.getElementById('contentx').innerHTML = content;
	content = sFilename;
	document.getElementById('numx').innerHTML = content;

}

function set_selection(delta)
{
	var new_col = selected_col + delta;
	if ((new_col >= 1) && (new_col <= 5))
	{
		set_selection_cnt(new_col);
		return;
	}
	if (new_col < 1)
	{
		get_content(-1);
		return;
	}
	if (new_col > 5)
	{
		get_content(+1);
		return;
	}
}