.presentation{margin:0 auto;margin-top:50px;text-align:center;}.presentation a_btn{width:69px;height:17px;line-height:17px;text-align:center;display:block;float:left;margin-left:10px;background:url(../images/error_btnbg.jpg) no-repeat center center;}.presentation_p{color:#000;text-align:center;line-height:40px;}.presentation_p a{color:#FA5200}.presentation_btn{height:20px;width:100px;margin:0 auto;padding:30px 0;color:#1D923A;}.presentation_btn a{color:#1D923A;}.presentation_btns{height:20px;width:180px;margin:0 auto;padding:30px 0;}