Dreamweaver CS5 jump menu behavior is as follows:

1. Select the jump menu object in the document.

2. Open the Behaviors panel.

3. Click the Add Behavior (+) button and select the Jump Menu command from the pop-up drop-down menu. As shown in the figure below:

4. Open the Jump Menu dialog box,

5. Make changes in the Jump Menu dialog box as needed. If it is a frame page, there will be a frame window to choose from in the "Open URL in:" drop-down box.

6. Click the OK button.