To set attribute values, click in the Value field to the right of an attribute and enter a value.
Some attributes contain default values. Also, when you click in some Value fields, the field:
Becomes a combo box from which you select a value
Displays a button that you click to enter the value in a dialog.
For combo box Value fields where you do not want to specify a value, select the empty white box at the end of the combo box list. This removes the attribute from the DOM and avoids creating an attribute with an empty string and wasting unnecessary bandwidth.
Note: For file-based attributes, you can open a file dialog to select the file. For example, you can browse an application directory to select an image file to use as an image on a button.