if(navigator.appVersion.charAt(0) >=3){
        var topimg = new Array();
                for( i = 0 ; i < 4 ; i++ ){
                topimg[i] = new Image();
        }
        topimg[0].src= "../../img/home_hed01.jpg";
        topimg[1].src= "../../img/home_hed02.jpg";
        topimg[2].src= "../../img/home_hed03.jpg";
        topimg[3].src= "../../img/home_hed04.jpg";
}





//
//　乱数発生
//

function unixOrnot() {
	if (navigator.appVersion.lastIndexOf('Unix') != 1)
	return true
	else
	return false;
}
function randomNum() {
	if (unixOrnot()) {
	num = Math.random()
	}
	else {
	num = Math.abs(Math.sin(Date.getTime()));
	}
	return num;
}


//
//　ページ上部の画像をランダムに表示
//
function topImage() {
	var nc;
	randomNum();
	nc = Math.floor( num * 4);
	if ( nc == 1 ) {
	        if(navigator.appVersion.charAt(0) >= 3 ) {
	                document.images['topimage01'].src=topimg[1].src;
		}
	} else if ( nc == 2 ) {
	        if(navigator.appVersion.charAt(0) >= 3 ) {
	                document.images['topimage01'].src=topimg[2].src;
		}
	} else if ( nc == 3 ) {
	        if(navigator.appVersion.charAt(0) >= 3 ) {
	                document.images['topimage01'].src=topimg[3].src;
		}
	} else {
	        if(navigator.appVersion.charAt(0) >= 3 ) {
	                document.images['topimage01'].src=topimg[0].src;
		}
	}

}