Qurey- Where Issue

I have a list box that is updated by a query, here is my query:
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SELECT [Work Order Content].[WO ID], [Work Order Content].[Work Order Number], [Work Order Content].[WO Date Ordered], [Work Order Content].[WO Date Needed]
FROM [Work Order Content]
WHERE ([Work Order Content].[Work Order Number]=Forms![open Doc]![WO Number]) Or ([Work Order Content].[WO date ordered]=Forms![open Doc]![WO date ordered])
ORDER BY [Work Order Content].[WO ID];
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In the form I have textboxes to set the criteria, what I want is for this to be subtractive, when I open the form all Work Orders are shown and as I change criteria it weeds out Work orders that don't fit the criteria. What must I change to fulfill this requirement. I personally was thinking there must be something better than 'OR' to use, but I really have no idea.