Javascript show/hide function in safari

<script type="text/javascript">

	    function Show_Hide_Display() {
	        var div1 = document.getElementById('<%=main_filter.ClientID%>');

		    if (div1.style.display == "" || div1.style.display == "block") {
		        div1.style.display = "none";
		    }
		    else {
		        div1.style.display = "block";
		    }
		    return false;
		}

	</script>

<pre><div class="col-md-6 col-xs-3 pull-right btn-mobile">
	<input type="button" class="btn btn-primary btn-block span3" id="closefilter" value="Done" onclick="Show_Hide_Display()" />
</div>

$(document).ready(function () {
           $("#closefilter").click(function () {
               $("main_filter").hide();
           });
       });

document.getElementByClassName