function loadCSS() {
	var dateObj = new Date();
	var hour = dateObj.getHours();
	var cssFile = "";
	
	if ( hour > 6 && hour < 19 ) {
		cssFile = "css/white.css";
	} else {
		cssFile = "css/black.css";
	}
	
	var cssObj = document.createElement('link');
	cssObj.setAttribute("rel", "stylesheet");
	cssObj.setAttribute("type", "text/css");
	cssObj.setAttribute("href", cssFile);
	document.getElementsByTagName("head")[0].appendChild(cssObj);
}

function navShow(textStr) {
	var textObj = document.getElementById("navText");
	if ( textObj.textContent ) {
		textObj.textContent = textStr;
	} else {
		textObj.innerText = textStr;
	}
}

function getScrollTop(){
    if(typeof pageYOffset!= 'undefined'){
        //most browsers
        return pageYOffset;
    }
    else{
        var B= document.body; //IE 'quirks'
        var D= document.documentElement; //IE with doctype
        D= (D.clientHeight)? D: B;
        return D.scrollTop;
    }
}

loadCSS();

window.onscroll = function() {
	var uagent = navigator.userAgent;
	
	if ( uagent.indexOf("iPhone") < 0 && uagent.indexOf("iPod") < 0 && uagent.indexOf("iPad") < 0 ) {
		var scrollObj = document.getElementById("scrollTop");
		
		var scrollTopValue = getScrollTop();
		
		if ( scrollTopValue > 300 ) {
			scrollObj.style.display = "block";
		} else {
			scrollObj.style.display = "none";
		}
	}
}

$(document).ready(function(){
    $(".scroll").click(function(event){
        event.preventDefault();
        var full_url = this.href;
        var parts = full_url.split("#");
        var trgt = parts[1];
        var target_offset = $("#"+trgt).offset();
        var target_top = target_offset.top;
        $('html, body').animate({scrollTop:target_top}, 500);
    });
});