via：http://www.hdky.edu.cn/rwkj/admin/templates/plugins/bootstrap/css/ie.css

ie.css

/* NAVBAR */

/* !CPU HIGH, fix for IE6 shake when scroll */
* html,* html body {
  _background-image:url(about:blank);
  _background-attachment:fixed;
}
/* !CPU HIGH, fix for IE6 not support fixed position */
.navbar-fixed-top {
  _position:absolute;
  _bottom:auto;
  _top:expression(eval(document.documentElement.scrollTop));
}
/* !CPU HIGH, fix for IE6 not support fixed position */
.navbar-fixed-bottom {
  _position:absolute;
  _bottom:auto;
  _top:expression(eval(document.documentElement.scrollTop+document.documentElement.clientHeight-this.offsetHeight-(parseInt(this.currentStyle.marginTop,10)||0)-(parseInt(this.currentStyle.marginBottom,10)||0)));
}

/* DROPDOWN */
.dropup,
.dropdown {
  *zoom:1;
}

/* CLOSE */
.close {
  _font-size: 15px;
}

.modal-header h3 {
  *display: inline;
  *zoom:1;
}

/* MODALS */
.modal-backdrop {
  _position: absolute;
  _top:0;
  _margin-top:0;
  _width:expression(eval(document.documentElement.scrollWidth));
  _height:expression(eval(document.documentElement.scrollHeight));
}
.modal {
  _position:absolute;
  _top:0;
  _margin-top:0;
  _top:expression(eval(document.documentElement.scrollTop));
}
.modal.fade.in {
  _filter:alpha(opacity=100);
}
.modal-backdrop {
  _filter: alpha(opacity=80);
}
.modal-body {
  _height:expression(this.scrollHeight > 400 ? "400px" : "auto");
}