Creating SQL Statement

I have a search page to which one of the search criteria is Value. For this i have created two drop down menu's and populated them myself with the values i want the user to search by i.e between 0 & 500000 etc. I just cant get it to work, can someone pls check out the SQL code below and see where i am going wrong. firstvalue and secondvalue are the names of the dropdowns on the search page.

CODE:

SELECT *
FROM FactQRY
WHERE project LIKE '%proj%' AND location LIKE '%loc%' AND project_type LIKE '%type%' AND client_name LIKE '%client%' AND value_id >= 'firstvalue' AND value_id <= 'secondvalue'