I need to construct a query that prompts for three variables - one is customer name and exists on a table, the others are between dates and a yes/no answer. I can get the parameter prompt OK but how do i get it to present a drop down list of customers (or can it?) as this will reduce possible keying errors.

You can't.

To present the user with a drop down list you must create a form containing a combo box, and obviously you would add your other parameters to the same form.
Then refer to the form controls in your query criteria.

forms!formname!comboboxname

Thanks for that - never thought about using a form....

Slight problem - have mesde these changes - creating a form and then adding a command button to run the query having filled in the combo box and referenced the query crietria to the right boxes.

However, when you click the run query button I get the parameter query boxes up with the prompt forms!formname!comboxname.

What am I doing wrong?

Please post the sql view of your query.