function gOb(id){
	return document.getElementById(id);
}

function startup_functions(){
	form_colorchanger();
	if(document.cookie){
		var show_header_img = getCookie("show_header_img");
		if(show_header_img == "no"){
			gOb("header_img_container").style.display = "none";
			gOb("header_open").style.visibility = "visible";
		}
	}
}

function switch_header_img(){
	var expires = new Date();
	var timeStamp = expires.getTime() + (5 * 24 * 60 * 60 * 1000);
	expires.setTime(timeStamp);
	expires.toGMTString();
	
	if(gOb("header_img_container").style.display == "none"){
		gOb("header_img_container").style.display = "block";
		gOb("header_open").style.visibility = "hidden";
		setCookie("show_header_img","yes",expires);
	}else{
		gOb("header_img_container").style.display = "none";
		gOb("header_open").style.visibility = "visible";
		setCookie("show_header_img","no",expires);
	}
}

function form_colorchanger(color_1,color_2,use_tags,input_types){
	var color_1 =  color_1 || "#fff1c6";
	var color_2 =  color_2 || "#ffffff";
	
	function set_active_status(){
		this.style.backgroundColor = color_1;
	};
	function set_passive_status(){
		this.style.backgroundColor = color_2;
	};
	
	// define elements & attributes 
	var use_tags = use_tags || "input,select,textarea";
	var use_inputtypes = input_types || "text,password";
	
	var tags = use_tags.split(",");
	var inputtypes = use_inputtypes.split(",");
	
	for(var i=0;i<tags.length;i++){
		var elem = document.getElementsByTagName(tags[i]);
		
		for(var a=0;a<elem.length;a++){
			for(var b=0;b<inputtypes.length;b++){
				if((elem[a].tagName == "INPUT" && elem[a].type == inputtypes[b]) || elem[a].tagName != "INPUT"){
					elem[a].onfocus = set_active_status;
					elem[a].onblur = set_passive_status;	
				}
			}
		}
	}
}

function img_popup(img,width,height){
	var left = screen.width/2 - width/2;
	var top = screen.height/2 - height/2;
	var img_popup = window.open("img_popup/img_popup.htm?img="+img,"img_popup","width="+width+",height="+height+",left="+left+",top="+top);
	img_popup.focus();	
}