function showPop(){

var popUp = document.getElementById('box_articles');
var left = 0;
var top = 0;
while (popUp) {
        left += popUp.offsetLeft;
        top += popUp.offsetTop;
        popUp = popUp.offsetParent;
}
var makeVisible = document.getElementById('sig_container');
makeVisible.style.visibility = 'visible';
makeVisible.style.left = left - 400 + 'px';
makeVisible.style.top = top - 400 + 'px';
}

function hidePop(){
var popUp = document.getElementById('sig_container');
popUp.style.visibility = "hidden";
}

if(document.images){
	var a1 = new Image();
	a1.src = '/graphics/corp/nav3.png';

}

function navChange(nav_num){
var changeImg = document.getElementById(nav_num);
switch(nav_num){
	case 'box_top1':
		changeImg.style.backgroundImage = "url(" + a1.src +")";

		break;
	case 'box_top2':
		changeImg.style.backgroundImage = "url(" + a1.src +")";

		break;
	case 'box_top3':
		changeImg.style.backgroundImage = "url(" + a1.src +")";

		break;
	case 'box_top4':
		changeImg.style.backgroundImage = "url(" + a1.src +")";

		break;
	case 'box_top5':
		changeImg.style.backgroundImage = "url(" + a1.src +")";

		break;
	}
}

function navBack(nav_num){

var changeImg = document.getElementById(nav_num);

switch(nav_num){
	case 'box_top1':
		changeImg.style.backgroundImage = "url('/graphics/corp/p_nav1.png')";
		break;
	case 'box_top2':
		changeImg.style.backgroundImage = "url('/graphics/corp/p_nav1.png')";
		break;
	case 'box_top3':
		changeImg.style.backgroundImage = "url('/graphics/corp/p_nav1.png')";
		break;
	case 'box_top4':
		changeImg.style.backgroundImage = "url('/graphics/corp/p_nav1.png')";
		break;
	case 'box_top5':
		changeImg.style.backgroundImage = "url('/graphics/corp/p_nav1.png')";
		break;
	}
}