Combo Box Control, Table Fields.
You can use the ListWidth property to set the width of the list box portion of a combo box.
The ListWidth property holds the width, in the current unit of measurement, of the list box portion of a combo box. To use a unit other than the default, include a measurement indicator, such as cm or in. The default setting (Auto) makes the list box portion of the combo box the same width as the combo box.
You can set the ListWidth property using the property sheet, a macro, or Visual Basic.
For table fields, you can set this property in table Design view for fields with the DisplayControl property set to Combo Box.
Note Microsoft Access sets this property automatically when you select Lookup Wizard as the data type for a field in table Design view.
In Visual Basic, use a numeric expression to set the value of this property. The default unit of measurement in Visual Basic is twips.
You can also set this property using a combo box’s default control style.
The list portion of the combo box can be wider than the combo box but can’t be narrower.
If you want to display a multiple-column list, enter a value that will make the list box wide enough to fit all the columns.
Tip When designing combo boxes, be sure to leave enough space to display your data and for Microsoft Access to insert a vertical scroll bar.
ListRows Property.