图片上传并显示（兼容ie），图片大小判断

HTML

<div id="swf" style="margin: 0 auto;text-align: center;">

    <img src="/assets/img/default.jpg" height="180px" width="180px"

         id="logoshow">

</div>

<div id="headview" style="text-align: center;margin: 0 auto;">

    <input type="file" id="logo" name="logo" style="width: 180px;"

           onchange="previewImage(this)">

</div>

JS

function previewImage(file){

    var div = document.getElementById('swf');

    if (file.files && file.files[0]) {//HTML5

        var img = document.getElementById('logoshow');

        var reader = new FileReader();

        reader.readAsDataURL(file.files[0]);

        reader.onload = function (evt) {

            img.src = evt.target.result;

            img.style.width= "180px";

        };

    }

    else //兼容IE，滤镜

    {

        alert("filter");

        var sFilter = 'filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="';

        file.select();

        file.blur();

        var src = document.selection.createRange().text;

        var img = document.getElementById('logoshow');

        img.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = src;

        div.innerHTML = "<img id=logoshow style='margin:0px auto;width:180px;height:180px;" + sFilter + src + "\"'>";

    }

}

JS判断文件大小

<input id="file" type="file" onchange="filefujianChange(document.getElementById('file'))">

<script type="text/javascript">

	function filefujianChange(target) {

		var fileSize = 0;

		if (!target.files) {

			var filePath = target.value;

			var fileSystem = new ActiveXObject("Scripting.FileSystemObject");

			var file = fileSystem.GetFile (filePath);

			fileSize = file.Size;

		} else {

			fileSize = target.files[0].size;

		}

		var size = fileSize / 1024;

		alert(size);

		if(size>2000){

			alert("附件不能大于2M");

			target.value="";

			return

		}

		var name=target.value;

		var fileName = name.substring(name.lastIndexOf(".")+1).toLowerCase();

		alert(fileName);

		if(fileName !="jpg" && fileName !="jpeg" && fileName !="pdf" && fileName !="png" && fileName !="dwg" && fileName !="gif" ){

			alert("请选择图片格式文件上传(jpg,png,gif,dwg,pdf,gif等)！");

			target.value="";

			return ;

		}

	}

</script>