var el="col_all";
	  var bgimg=new Array("../rcol_img/ban_img_01.jpg", "../rcol_img/ban_img_02.jpg","../rcol_img/ban_img_03.jpg","../rcol_img/ban_img_04.jpg","../rcol_img/ban_img_05.jpg");
	  var random=Math.round((bgimg.length-1)*Math.random());
	  var cssStr="#"+el+" { background: url("+bgimg[random]+") no-repeat bottom left } ";
	  var style=document.createElement("style");style.setAttribute("type","text/css");
	    if(style.styleSheet){style.styleSheet.cssText=cssStr;}
	    else{
	      var cssText=document.createTextNode(cssStr);style.appendChild(cssText);}document.getElementsByTagName("head")[0].appendChild(style);