my web pages are not working correctly ?syntax error

Hi please help I'm very new to all this ! I edited my web pages to enter keywords for google optimization but since then my website is not working correctly the site is a shop (www.chandlerybarge.co.uk) but when you click on a category form the homepage nothing happens. I have deleted what i changed but this has made no difference and I did't back up files before publishing! on the product.asp page it comesup with this message:
An error occurred executing the following query;
SELECT PT_Live, PT_Name1, P_StrapLine1, P_Live, P_Name1, P_SpecTable1, P_Desc1, P_HyperLink1, P_OrderVersionsBy, P_VersionDisplayType FROM (((tblCactuShopVersions INNER JOIN tblCactuShopTaxRates ON tblCactuShopVersions.V_Tax = tblCactuShopTaxRates.T_ID) INNER JOIN tblCactuShopProducts ON tblCactuShopVersions.V_Product = tblCactuShopProducts.P_ID) INNER JOIN tblCactuShopProductProdTypeLink ON tblCactuShopProducts.P_ID = tblCactuShopProductProdTypeLink.PPT_ProductID) INNER JOIN tblCactuShopProdtype ON tblCactuShopProductProdTypeLink.PPT_ProdTypeID = tblCactuShopProdtype.PT_ID WHERE P_ID= AND V_Live='y' AND P_Live='y' AND PT_Live='y'
Error Description :

Syntax error (missing operator) in query expression 'P_ID= AND V_Live='y' AND P_Live='y' AND PT_Live='y''.
I have tried contacting Cactushop but no help at all. What have I done and what should I do to fix it? Please help!!!