disablehistory Obsolete since Gecko 2.0false, an arrow button will appear on the end of the textbox which will open a dropdown menu of all available results. The default value is true, hiding the dropdown button. This attribute only works correctly in SeaMonkey 1.x; for Thunderbird and SeaMonkey 2.0 you should also set the enablehistory attribute; as of Gecko 2.0 this attribute is completely superseded by it.