If you have disabled your eMiniMalls search tab in order to comply with AdSense terms and policies, you can re-enable it. Because it is not a web search tool, but only a product search tool within eMiniMalls, publishers are permitted to run AdSense on the same page as eMiniMalls with the search tab.
This is the line you can remove:
ch_nosearch = 1;
Do remember you still must turn off contextual targeting to comply with AdSense, if you plan to run both on the same page.