<form method="GET" name="frm1" action="filterrange.php">
        <div class="dropdown" id="myDropdown">
            <button type="button" class="btn" data-toggle="dropdown">
                <i class="fa fa-filter" aria-hidden="true"></i>&nbsp;&nbsp;RANGE
            </button>

        <div class="dropdown-menu dropdown-menu-right ml-4">
            <div class="row rounded">
                <div class="col-12 col-sm-12 col-md-4 col-lg-4">
                    <div class="mt-1" style="text-align: center;">
                        <h5 class="border border-secondary rounded">YEAR</h5>
                    </div>
                </div>

                <div class="col-12 col-sm-12 col-md-4 col-lg-4">
                    <div class="range-slider mt-2 ml-1" style="">
                        <input class="range-slider__range ids" style="width:55%;"  type="range" name="range" value="2018" min="1990" max="2018">
                        <span class="ml-5 range-slider__value" style="font-size:20px;">0</span>
                    </div>
                </div>

                <div class="col-12 col-sm-12 col-md-4 col-lg-4">
                    <div class="abc mb-2" style="text-align: center;">
                        <button class="btn btn-primary my-2 my-sm-0" value="Search source code" name="submit" type="submit">Search</button>
                    </div>
                </div>

            </div>
        </div>
        </div>
    </form>