jQuery.extend({
    createUploadIframe: function(id, uri)
	{
            var frameId = 'jUploadFrame' + id;
            if(window.ActiveXObject) {
                var io = document.createElement('<iframe id="' + frameId + '" 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)
	{
		var 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);
		$(form).css('position', 'absolute');
		$(form).css('top', '-1200px');
		$(form).css('left', '-1200px');
		$(form).appendTo('body');		
		return form;
    },
    ajaxFileUpload: function(s) {
        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;		
        if ( s.global && ! jQuery.active++ ) jQuery.event.trigger( "ajaxStart" );
        var requestDone = false;
        var xml = {};   
        if ( s.global ) jQuery.event.trigger("ajaxSend", [xml, s]);
        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";
                    if ( status != "error" )
					{
                        var data = jQuery.uploadHttpData( xml, s.dataType );    
                        if ( s.success ) s.success( data, status );
    
                        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);
                };
                if ( s.global ) jQuery.event.trigger( "ajaxComplete", [xml, s] );
                if ( s.global && ! --jQuery.active ) jQuery.event.trigger( "ajaxStop" );
                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;
            }
        }
        if ( s.timeout > 0 ) 
		{
            setTimeout(function(){
                if( !requestDone ) uploadCallback( "timeout" );
            }, s.timeout);
        }
        try 
		{
			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 ( type == "script" ) jQuery.globalEval( data );
        if ( type == "json" ) eval( "data = " + data );
        if ( type == "html" ) jQuery("<div>").html(data).evalScripts();
        return data;
    }
});