// JavaScript Document

function changepic(img_name) {
	var check = document[img_name].src.replace(window.location,'');
	var img_up = 'images/nav_' + img_name + '.jpg';
	var img_over = 'images/nav_' + img_name + '_over.jpg';
	if(check == img_up){
		document[img_name].src = img_over;
	}else{
		document[img_name].src = img_up;
	}
}