//
//	hide or show a span
//	also support hide_clear whcih empties the contents of the span
//
function _spanSetVisible(span, is_visible)
{
    if (is.ie) 
    {
        if (is_visible=='hide_clear')
		{
	        span.style.visibility = 'hidden';
			span.innerHTML='';
		}
		else
		{
	        span.style.visibility = is_visible;
		}
	}
	else if (is.ns)
	{
		if (is_visible=='hide_clear')
		{
			span.visibility = 'hidden';

			span.document.open();
			span.document.write();
			span.document.close();
		}
		else
		{
			span.visibility = is_visible;
		}
	}
}

function _spanShow(span)
{
	_spanSetVisible(span, 'visible');
}

function _spanHide(span) 
{
	_spanSetVisible(span, 'hidden');
}

function _spanHideClear(span)
{
	_spanSetVisible(span, 'hide_clear');
}

function _spanMove(span, x, y)
{
    if (is.ie) 
	{ 
		span.style.pixelLeft=x;
		span.style.pixelTop=y;
	}
	else if (is.ns)
	{ 
		span.left = x;
		span.top = y;
	}
}

function _spanGetClip(span, which) 
{
    if (is.ie) 
    {
    	var clipv = span.clip.split("rect(")[1].split(")")[0].split("px")
        if (which=="t") return Number(clipv[0])
        if (which=="r") return Number(clipv[1])
        if (which=="b") return Number(clipv[2])
        if (which=="l") return Number(clipv[3])
        if (which=="h") return Number(clipv[2])-Number(clipv[0])
        if (which=="w") return Number(clipv[3])-Number(clipv[1])
	}
	else if (is.ns)
	{
    	if (which=="t") return span.clip.top
        if (which=="r") return span.clip.right
        if (which=="b") return span.clip.bottom
        if (which=="l") return span.clip.left
        if (which=="h") return span.clip.height
        if (which=="w") return span.clip.width
	}
}

function _spanClearClip(span)
{
    if (is.ie) 
	{
		span.clip = '';
	}
	else if (is.ns)
    {
		span.clip.top = 0;
		span.clip.left = 0;
		span.clip.width = 0;
		span.clip.height = 0;
	}
}

function _spanSetClip(span, t, r, b, l)
{
    if (is.ie) 
	{
		span.clip = "rect(" + t + "px " + r + "px " + b + "px " + l + "px)";
	}
	else if (is.ns)
    {
		span.clip.top = t;
		span.clip.right = r;
		span.clip.bottom = b;
		span.clip.left = l;
	}
}


function _spanSetClip(span, which, value) 
{
    if (is.ie) 
    {
    	var clipv = span.clip.split("rect(")[1].split(")")[0].split("px");

		var t = Number(clipv[0]);
		var r = Number(clipv[1]);
		var b = Number(clipv[2]);
		var l = Number(clipv[3]);
		var h = Number(clipv[2])-Number(clipv[0]);
		var w = Number(clipv[3])-Number(clipv[1]);

        if (which=="t")
		{
			t = value;
		}
        else if (which=="r")
		{
			r = value;
		}
        else if (which=="b")
		{
			b = value;
		}
        else if (which=="l")
		{
			l = value;
		}
        else if (which=="w")
		{
			w = value;
			r = l + w;
		}
        else if (which=="h")
		{
			h = value;
			b = t + h;
		}

		_spanSetClip(span, t, r, b, l);
	}
	else if (is.ns)
	{
    	if (which=="t") span.clip.top = value;
        if (which=="r") span.clip.right = value;
        if (which=="b") span.clip.bottom = value;
        if (which=="l") span.clip.left = value;
        if (which=="w") span.clip.width = value;
        if (which=="h") span.clip.height = value;
	}
}

function _spanSetClipDelta(span, which, delta) 
{
	var value = _spanSetClip(span, which)+delta;
	_spanSetClip(span, which, value);
}

function _spanClip(span, obj) 
{ 
    if (is.ie) 
	{ 
		span.clip = "rect(" + obj.top + "px " + obj.right + "px " + obj.bottom + "px " + obj.left + "px)" 
	} 
	else if (is.ns)
	{ 
		span.clip.top = obj.top 
		span.clip.left = obj.left 
		span.clip.bottom = obj.bottom 
		span.clip.right = obj.right 
	}
}  

// not finished for NS width and height ...
function _spanSetSize(span, x, y, width, height)
{
    if (is.ie) 
	{ 
		span.style.pixelLeft=x;
		span.style.pixelTop=y;
		span.style.pixelWidth=width;
		span.style.pixelHeight=height;
	}
	else if (is.ns)
	{ 
		span.left = x;
		span.top = y;
		//span.clip.width=width;
		//span.clip.height=height;
	}
}