ajaxfileupload.js 支持chrome，fireox，ie

jQuery.extend({handleError: function( s, xhr, status, e ) {// If a local callback was specified, fire itif ( s.error ) {s.error.call( s.context || s, xhr, status, e );}// Fire the global callbackif ( s.global ) {(s.context ? jQuery(s.context) : jQuery.event).trigger( "ajaxError", [xhr, s, e] );}},    createUploadIframe: function(id, uri){//create frame            var frameId = 'jUploadFrame' + id;            if(window.ActiveXObject) {            var mm='<iframe id="' + frameId + '" name="' + frameId + '" />';                //var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');                var io = document.createElement('iframe');                io.id = frameId;            io.name= frameId;                if(typeof uri== 'boolean'){                    io.src = 'javascript:false';                }                else if(typeof uri== 'string'){                    io.src = uri;                }            }            else {                            var io = document.createElement('iframe');                io.id = frameId;                io.name = frameId;            }            io.style.position = 'absolute';            io.style.top = '-1000px';            io.style.left = '-1000px';            document.body.appendChild(io);            return io;    },    createUploadForm: function(id, fileElementId){//create formvar formId = 'jUploadForm' + id;var fileId = 'jUploadFile' + id;var form = $('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');var oldElement = $('#' + fileElementId);var newElement = $(oldElement).clone();$(oldElement).attr('id', fileId);$(oldElement).before(newElement);$(oldElement).appendTo(form);//set attributes$(form).css('position', 'absolute');$(form).css('top', '-1200px');$(form).css('left', '-1200px');$(form).appendTo('body');return form;    },    ajaxFileUpload: function(s) {        // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout        s = jQuery.extend({}, jQuery.ajaxSettings, s);        var id = new Date().getTime()      var form = jQuery.createUploadForm(id, s.fileElementId);var io = jQuery.createUploadIframe(id, s.secureuri);var frameId = 'jUploadFrame' + id;var formId = 'jUploadForm' + id;        // Watch for a new set of requests        if ( s.global && ! jQuery.active++ ){jQuery.event.trigger( "ajaxStart" );}                    var requestDone = false;        // Create the request object        var xml = {}           if ( s.global )            jQuery.event.trigger("ajaxSend", [xml, s]);        // Wait for a response to come back        var uploadCallback = function(isTimeout){var io = document.getElementById(frameId);            try {if(io.contentWindow){ xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;                 xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document; }else if(io.contentDocument){ xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;                xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;}            }catch(e){    jQuery.handleError(s, xml, null, e);}            if ( xml || isTimeout == "timeout") {                requestDone = true;                var status;                try {                    status = isTimeout != "timeout" ? "success" : "error";                    // Make sure that the request was successful or notmodified                    if ( status != "error" ){                        // process the data (runs the xml through httpData regardless of callback)                        var data = jQuery.uploadHttpData( xml, s.dataType );                            // If a local callback was specified, fire it and pass it the data                        if ( s.success )                            s.success( data, status );                            // Fire the global callback                        if( s.global )                            jQuery.event.trigger( "ajaxSuccess", [xml, s] );                    } else                        jQuery.handleError(s, xml, status);                } catch(e) {                    status = "error";                    jQuery.handleError(s, xml, status, e);                }                // The request was completed                if( s.global )                    jQuery.event.trigger( "ajaxComplete", [xml, s] );                // Handle the global AJAX counter                if ( s.global && ! --jQuery.active )                    jQuery.event.trigger( "ajaxStop" );                // Process result                if ( s.complete )                    s.complete(xml, status);                jQuery(io).unbind()                setTimeout(function(){try {$(io).remove();$(form).remove();} catch(e) {jQuery.handleError(s, xml, null, e);}}, 100)                xml = null            }        }        // Timeout checker        if ( s.timeout > 0 ) {            setTimeout(function(){                // Check to see if the request is still happening                if( !requestDone ) uploadCallback( "timeout" );            }, s.timeout);        }                try {           // var io = $('#' + frameId);var form = $('#' + formId);$(form).attr('action', s.url);$(form).attr('method', 'POST');$(form).attr('target', frameId);            if(form.encoding){                form.encoding = 'multipart/form-data';            }            else{                form.enctype = 'multipart/form-data';            }            $(form).submit();        } catch(e) {              jQuery.handleError(s, xml, null, e);        }        if(window.attachEvent){            document.getElementById(frameId).attachEvent('onload', uploadCallback);        }        else{            document.getElementById(frameId).addEventListener('load', uploadCallback, false);        }         return {abort: function () {}};    },    uploadHttpData: function( r, type ) {        var data = !type;        data = type == "xml" || data ? r.responseXML : r.responseText;        // If the type is "script", eval it in global context        if ( type == "script" )            jQuery.globalEval( data );        // Get the JavaScript object, if JSON is used.        if ( type == "json" )        {            //alert(data);            data = eval("(" + data + ")");           // eval( "data = " + data );            //alert(data);        }        // evaluate scripts within html        if ( type == "html" )            jQuery("<div>").html(data).evalScripts();//alert($('param', data).each(function(){alert($(this).attr('value'));}));        return data;    }})