// 内高(paddingを含み、スクロールバー,border,marginを除く)を求める
function getINNERHEIGHT(){
	if(window.opera)
		return document.body.clientHeight				//o6,o7用
	else if(document.all)
		return document.documentElement.clientHeight	//e4,e5,e6用
	else if(document.getElementById)
		return window.innerHeight						//n6,n7,m1,s1用
	return null
}


function WinResize(){
	// ブラウザの高さ
	var windowheight = parseInt(getINNERHEIGHT());
	if ( windowheight > 600 ) {
		window.document.getElementsByTagName("body")[0].style.marginTop = parseInt((windowheight - 600) / 2) + "px";
	} else {
		window.document.getElementsByTagName("body")[0].style.marginTop = 0;
	}
}

window.onresize = WinResize;
//window.onresize = ImageChange;