A typical synon screen looks like following image
This image shows you that a synon Screen has Header, Control, Detail and a Footer.
Following screen show the contexts you have to address fields on the screen.
In design screen mode you can always press Shift+F5 to Add/drop/hide fields from your screen. You will know once you get into that menu.
Suppose you want to change fields display name etc..Put cursor on any field on screen and hit enter to see Field properties. To do magic with a field like color, Highlight, Blink etc..press Shift+F7 from Field properties and next screen will open. You will know what to do and how to do when new screen opens
Suppose you want that a list of value should open when F4 is pressed on a field. In Screen design mode hit enter on the field and Field properties screen will open. Supply your list values in "Check Condition" option.
Device Design function keys
F1 moves the field 40 positions to the left.
F2 animates the panel using Toolkit.
F3 exits the panel.
F4 moves the field 40 columns to the right.
F5 edits device format details of the format where the cursor is positioned.
F6 cancels the pending operations.
F7 displays the Edit Device Design Format Relations panel.
F8 moves the selected field to the cursor position.
F9 wraps text onto the next line starting from the field on which the cursor is positioned.
F10 moves text one column to the right.
F11 removes the line on which the cursor is positioned.
F12 aligns text below the cursor position.
F13 fast exits the panel.
F15 moves panel window to the left margin.
F16 moves window to the right margin.
F17 displays a list of device formats.
F18 displays the Edit Field Attributes panel.
F19 adds new function fields to the device design.
F20 edits the function field on the device design.
F21 adds a line above the cursor position.
F22 moves text one column to the left.
F23 adds a constant field to the device design.
F24 aligns all fields under the cursor position.