Index: applications/editors/josm/plugins/imagery_offset_db/src/iodb/SimpleOffsetQueryTask.java
===================================================================
--- applications/editors/josm/plugins/imagery_offset_db/src/iodb/SimpleOffsetQueryTask.java	(revision 29372)
+++ applications/editors/josm/plugins/imagery_offset_db/src/iodb/SimpleOffsetQueryTask.java	(revision 29372)
@@ -0,0 +1,106 @@
+package iodb;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.*;
+import java.util.*;
+import java.util.regex.*;
+import javax.swing.JOptionPane;
+import org.openstreetmap.josm.Main;
+import org.openstreetmap.josm.gui.PleaseWaitRunnable;
+import org.openstreetmap.josm.io.OsmTransferException;
+import org.xml.sax.SAXException;
+import static org.openstreetmap.josm.tools.I18n.tr;
+
+/**
+ *
+ * @author zverik
+ */
+class SimpleOffsetQueryTask extends PleaseWaitRunnable {
+    private String query;
+    private String errorMessage;
+    private String title;
+    protected boolean cancelled;
+
+    public SimpleOffsetQueryTask( String query, String title ) {
+        super(tr("Uploading"));
+        this.query = query;
+        this.title = title;
+        cancelled = false;
+    }
+
+    public void setQuery( String query ) {
+        this.query = query;
+    }
+
+    @Override
+    protected void realRun() throws SAXException, IOException, OsmTransferException {
+        getProgressMonitor().indeterminateSubTask(title);
+        try {
+            errorMessage = null;
+            doQuery(query);
+        } catch( UploadException e ) {
+            errorMessage = tr("Server has rejected the request") + ":\n" + e.getMessage();
+        } catch( IOException e ) {
+            errorMessage = tr("Unable to connect to the server") + "\n" + e.getMessage();
+        }
+    }
+
+    private void doQuery( String query ) throws UploadException, IOException {
+        try {
+            URL url = new URL(ImageryOffsetTools.getServerURL() + query);
+            System.out.println("url=" + url);
+            HttpURLConnection connection = (HttpURLConnection)url.openConnection();
+            connection.connect();
+            if( connection.getResponseCode() != 200 ) {
+                throw new IOException("HTTP Response code " + connection.getResponseCode() + " (" + connection.getResponseMessage() + ")");
+            }
+            InputStream inp = connection.getInputStream();
+            if( inp == null )
+                throw new IOException("Empty response");
+            try {
+                if( !cancelled )
+                    processResponse(inp);
+            } finally {
+                connection.disconnect();
+            }
+        } catch( MalformedURLException ex ) {
+            throw new IOException("Malformed URL: " + ex.getMessage());
+        }
+    }
+
+    @Override
+    protected void cancel() {
+        cancelled = true;
+    }
+
+    @Override
+    protected void finish() {
+        if( errorMessage != null ) {
+            JOptionPane.showMessageDialog(Main.parent, errorMessage, tr("Imagery Offset"), JOptionPane.ERROR_MESSAGE);
+        }
+    }
+
+    protected void processResponse( InputStream inp ) throws UploadException {
+        String response = "";
+        if( inp != null ) {
+            Scanner sc = new Scanner(inp).useDelimiter("\\A");
+            response = sc.hasNext() ? sc.next() : "";
+        }
+        Pattern p = Pattern.compile("<(\\w+)>([^<]+)</\\1>");
+        Matcher m = p.matcher(response);
+        if( m.find() ) {
+            if( m.group(1).equals("error") ) {
+                throw new UploadException(m.group(2));
+            }
+        } else {
+            throw new UploadException("No response");
+        }
+    }
+
+    public static class UploadException extends Exception {
+        public UploadException( String message ) {
+            super(message);
+        }
+    }
+}
Index: applications/editors/josm/plugins/imagery_offset_db/src/iodb/UploadDialog.java
===================================================================
--- applications/editors/josm/plugins/imagery_offset_db/src/iodb/UploadDialog.java	(revision 29372)
+++ applications/editors/josm/plugins/imagery_offset_db/src/iodb/UploadDialog.java	(revision 29372)
@@ -0,0 +1,42 @@
+package iodb;
+
+import java.awt.BorderLayout;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import javax.swing.*;
+import org.openstreetmap.josm.Main;
+import static org.openstreetmap.josm.tools.I18n.tr;
+
+/**
+ * A dialog for uploading stuff. Can be extended for different types of offsets.
+ * 
+ * @author zverik
+ */
+public class UploadDialog extends JDialog implements ActionListener {
+
+    public UploadDialog() {
+        super(JOptionPane.getFrameForComponent(Main.parent), tr("Imagery Offset"), ModalityType.DOCUMENT_MODAL);
+        setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
+    }
+    
+    private void prepareDialog() {
+        JPanel dialogPanel = new JPanel(new BorderLayout());
+        setContentPane(dialogPanel);
+        pack();
+        setLocationRelativeTo(Main.parent);
+    }
+
+    public ImageryOffsetBase showDialog() {
+        prepareDialog();
+        setVisible(true);
+        return null;
+    }
+    
+    protected void constructImageryOffset() {
+        
+    }
+
+    public void actionPerformed( ActionEvent e ) {
+        setVisible(false);
+    }
+}