// JavaScript Document

function bodyBack() {
	if (screen.width<=1024)
		document.body.style.backgroundImage="url(../pic/body_back_1024.jpg)";
	else if (screen.width>1024 && screen.width<=1440)
		document.body.style.backgroundImage="url(../pic/body_back_1440.jpg)";
	else if (screen.width>1440)
		document.body.style.backgroundImage="url(../pic/body_back_1920.jpg)";		
}