HTML5 API Create Object

var url = window.URL || window.webkitURL;
var checkFileSize = function(file){
var size = {
imgEXP:{width:286,height:126},
imgKnowledge:
[
{width:490,height:324},
{width:235,height:215}
]
 };
if(file.label == "imgEXP"){
return (file.width > size.imgEXP.width || file.height > size.imgEXP.height)?false:true;
}
else{
if(file.label == "imgKnowledgeL") // Image large size
return (file.width > size.imgKnowledge[0].width || file.height > size.imgKnowledge[0].height)?false:true;
else if(file.label == "imgKnowledgeS") // Image small size
return (file.width > size.imgKnowledge[1].width || file.height > size.imgKnowledge[1].height)?false:true;
}
};

$('input[name="img"], input[name="imgL"], input[name="imgS"]').change(function(e) {
console.log($(this).val());
$.post(
'checking.php?check=contents&action=checkImageSize',
{img:$(this).val()},
function(data){
console.log(data);
alert(data);
}
);
if( $.browser.msie && $.browser.version <= 9 ){
alert('Your browser does not support File upload.');
}
else{
var img = new Image(),
chosen = this.files[0],
labelClass = $(this).attr('label'),
file = {};

img.onload = function() {
file = {label:labelClass, width:this.width, height:this.height};

if( !checkFileSize(file) )
alert(this.width+' x '+this.height+' ไฟล์เกินขนาดที่กำหนด.')
else
console.log('true');
}
img.onerror = function() {
            alert('ชนิดของไฟล์ไม่ถูกต้อง: '+ chosen.type);
        };
img.src = url.createObjectURL(chosen);
}
});