SQL Reporting Services and multiple field (not database) search

I have the sql query below and would like to know how to get it to just ask for the parameter @part but also do a or search on the description field. The way it is now it asks or both.

thanks,
newbie
SELECT PART.ID, PART.DESCRIPTION, PART.ABC_CODE, PART.UNIT_MATERIAL_COST, PART.QTY_ON_HAND, VENDOR_QUOTE.MFG_NAME,
VENDOR_QUOTE.MFG_PART_ID, PART.USER_3, PART.USER_4, PART.USER_5, PART.USER_6, PART.USER_7, PART.USER_8,
VENDOR_PART.VENDOR_PART_ID, VENDOR.NAME AS Vendor_Name, PART.PREF_VENDOR_ID
FROM VENDOR_QUOTE INNER JOIN
VENDOR ON VENDOR_QUOTE.VENDOR_ID = VENDOR.ID RIGHT OUTER JOIN
PART LEFT OUTER JOIN
VENDOR_PART ON PART.ID = VENDOR_PART.PART_ID ON VENDOR.ID = VENDOR_PART.VENDOR_ID
WHERE (PART.ID = @Part) OR
(PART.DESCRIPTION = @DESC)