$(document).ready( checkNavigationOffset );

function checkNavigationOffset()
{
	var upperEnd = getLateralOffset($('#upper .end')[0]);
	var upperwidth =  upperEnd - getLateralOffset($('#upper')[0]);

	var position = 0;
	var set = $('#upper li');
	
	for(position = 0 ; position < set.length ; position++)
		if($(set.get(position)).hasClass('location'))
			break;
	
	paddingLeft = (position / set.length) * upperwidth;
	$('#lower').css('padding-left' , paddingLeft + "px");

	lowerRightProtrusion = getLateralOffset($('#lower .end')) - upperEnd;
	$('#lower').css('padding-left' , paddingLeft - (lowerRightProtrusion < 0 ? 0 : lowerRightProtrusion) + "px");
}

function getLateralOffset(obj)
{
    var curleft = 0;
    if(obj.offsetParent)
	    while(1) 
        {
          curleft += obj.offsetLeft;
          if(!obj.offsetParent)
            break;
          obj = obj.offsetParent;
        }
    else if(obj.x)
        curleft += obj.x;
    return curleft;
}