Got this error while working on a Joomla 1.5.18, Virtuemart 1.1.4 website.
Error: $("vmlp_search_str").addEvent is not a function
Source File: http://www.tracyeinny.com.sg/staging2/modules/mod_vm_live_product/js/vmliveproduct.js
After debugging for a while. I found out that apparently there are conflicts between jQuery and Mootools (or other scripts).
To solve this, just need to add in the following scripts after jQuery import.