I am using FileReader API, here is the sample code. I tried all of the read*** methods, none of them works. Always got "invalid data error". I need to evaluate the product before deciding to buy or not. Please help asap. 

file = input.files[0];
fr = new FileReader();
fr.onload = cb;
//fr.readAsText(file);
fr.readAsDataURL(file);
//fr.readAsBinaryString(file);
//fr.readAsArrayBuffer(file);
}
}

function cb() {
var workbook = $.ig.excel.Workbook.load(fr.result);

}