var num = Math.random();
var num = num*4;
var num = Math.floor(num);

car = new Array("top_prius.swf","top_vellfire.swf","top_vellfire2.swf","top_stepwgn_rk.swf");//配列に背景色の種類を必要分入れる
car = car[num];//ランダムに取り出した数字の背景色が決まる
car = "flash/" + car;

document.write('<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0" width="790" height="386"><param name="movie" value="',car,'"><param name="quality" value="high"><embed src="',car,'" quality="high" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" width="790" height="386"></embed></object>');