001.JS validate file

function validate_file(obj, ext, size){    //validate file extension    var fileExt=obj.value.substr(obj.value.lastIndexOf(".")).toLowerCase();    if(fileExt!='.'+ext){        return -1;    }     //validate file size    var fileSize = 0;    var isIE = /msie/i.test(navigator.userAgent) && !window.opera;                if (isIE && !obj.files) {                   var filePath = obj.value;                     var fileSystem = new ActiveXObject("Scripting.FileSystemObject");            var file = fileSystem.GetFile (filePath);                        fileSize = file.Size;             }else {           fileSize = obj.files[0].size;         }     fileSize=Math.round(fileSize/1024);    if(fileSize>size){        return -2;    }        return 1;}