help : Custom object on Salesforce visualforce page not working in Internet Explorer

Hi i have one custom object and which is having one Salesforce Visualforce page and Controller as posted below. In there we can drag and drop (or)we can attach multiple files at a time ,which is working fine in "Google Chrome" for both functionality.But The drag and drop functionality is not working in "Internet Explorer",So Can you please help me to fix the problem?
Visual Force Page----->

<apex:page standardController="Customobject__C" extensions="AttachmentActionFunction">
<script type='text/javascript'>

var newWin=null;
function openLookupPopup()
{
var url="/apex/docutype/";

alert('$$$$$$$$$$'+ur1);
newWin=window.open(url, 'Popup','height=500,width=600,left=100,top=100,resizable=no,scrollbars=yes,toolbar=no,status=no');

}

function closeLookupPopup()
{
if (null!=newWin)
{
newWin.close();
}
}

var maxStringSize = 6000000;
var attachmentList;
var j;
function uploadFiles()
{
input = document.getElementById('fileinput');
attachmentList = input.files;
if(j == undefined)
j = 0;
var file;
if(j < attachmentList.length)
{
file = attachmentList[j];
var name = file.name;
var reader = new FileReader();
reader.onload = function(e) {
var attachmentbodybase64 = window.btoa(reader.result)
console.log(attachmentbodybase64.length);
if(attachmentbodybase64.length > maxStringSize )
alert("File size is too large to handle");
else
{
j++;
saveFileAF(attachmentbodybase64, name);
}
}
reader.readAsDataURL(file);
}
else
{
console.log('this is end');
var url = window.location.origin + '/'+"{!$CurrentPage.parameters.Id}";
console.log(url);
window.location.href = url;
}

}
</script>

<script>
function test(){

var url="/apex/docutype";

newWin=window.open(url, 'Popup','height=500,width=600,left=100,top=100,resizable=no,scrollbars=yes,toolbar=no,status=no');
console.log('$$$$$$$$$$'+ur1);
if (window.focus)
{
newWin.focus();
}

return false;

}
</script>

<apex:form >
<input type= "file" Id= "fileinput" multiple="multiple" />
<apex:commandButton value="Upload" onclick="test(); return false;" />
<apex:actionFunction name="saveFileAF"
action="{!saveFile}" oncomplete="test()" rerender="form" status="uploading">
<apex:param name="base64File" value="" assignTo="{!base64}"/>
<apex:param name="fileName" value="" assignTo="{!fileName}"/>
</apex:actionFunction>
<apex:actionStatus id="uploading" >
<apex:facet name="start" >
<img src="/img/loading.gif?x14128" />
</apex:facet>
</apex:actionStatus>
</apex:form>
</apex:page>

Controller---->

public class AttachmentActionFunction {

public transient String base64;
public Customobject__C Ins;

public List<Attachment> mulfiles{get;set;}

public Pagereference gotonewpage()
{
PageReference pageRef = Page.AttachmentActionFunction;
pageRef.getParameters().put('msg','success');
return PageRef;
}

public AttachmentActionFunction() {
mulfiles=new List<Attachment>();

}

public String getBase64()
{
return base64;
}
public void setbase64(String base64)
{
this.base64 = base64;
}
public String fileName {get; set;}
public AttachmentActionFunction(ApexPages.StandardController std)
{
Ins = (Customobject__C)std.getRecord();
}
public void saveFile()
{
Attachment a = new Attachment(parentId = Ins.id, Body = EncodingUtil.base64Decode(base64), name = fileName);

mulfiles=new List<Attachment>();

mulfiles.add(a);
//insert a;

}

public PageReference saveinline() {
return null;
}
}