var isIE = (document.getElementById && document.all)?true:false;
var isNS4 = (document.layers)?true:false;
var isNS6 = (document.getElementById && !document.all)?true:false;
function myGetElementById (id)
{
    if ( isIE )
    {
	var str = "document.all('" + id + "')";
	var o = eval(str);
	return o;
    }

    return document.getElementById(id);
}





// the main content ID



// these globals that can be used from other routines
var pageWidth;
var pageHeight;

// window.onload	= function() { findDimensions(); };
// window.onresize	= function() { findDimensions(); };

function findDimensions ()
{
    var frameWidth;
    var frameHeight;
    var obj;

    if (self.innerWidth)
    {
	frameWidth = self.innerWidth;
	frameHeight = self.innerHeight;
    }
    else if (document.documentElement && document.documentElement.clientWidth)
    {
	frameWidth = document.documentElement.clientWidth;
	frameHeight = document.documentElement.clientHeight;
    }
    else if (document.body)
    {
	frameWidth = document.body.clientWidth;
	frameHeight = document.body.clientHeight;
    }
    else
	return;

    // if there's valid info, update the globals so they can be used elsehere
    pageWidth = frameWidth;
    pageHeight = frameHeight;

    if ( (obj = myGetElementById('background')) )
    {
	obj.style.width = frameWidth;
	obj.style.height = frameHeight;
    }

    if ( (obj = myGetElementById('background_image')) )
    {
	var iWidth = obj.width; 
	var iHeight = obj.height;
	var iRatio = iWidth / iHeight;
	var fRatio = frameWidth / frameHeight;	

	// reset to default position on resize/load
	obj.style.top = obj.style.left = 0;

	if ( iRatio < fRatio ) 
	{
	    obj.style.width = frameWidth;
	    obj.style.height = frameWidth / iRatio;
	} 
	else 
	{
	    obj.style.height = frameHeight;
	    obj.style.width = frameHeight * iRatio;
	}
    }
}