Search Box Missing

I am using the heatmap theme. The search box was there until I inputted the adsense search code in its place by mistake. To correct the problem, I went into the theme options and deleted the code for the adsense search.

Now, the original search box is gone. I can still add another search box, but I can’t place it in its original position on the navigation bar where I would like it to be.

Thanks for any advice in advance.