jQuery Grid Plugin - jqGrid

I finally have jqGrid working like I want it to.  My next step is to integrate a website menu that will drive when the grid gets builts, where in the dom it gets built and with what static xml file.  I understand that jqGrid comes with gridUnload and gridDestroy.  Unload is only to be used when the column model is not to change (like viewing small arms data between 22 caliber and 45 caliber bullets).  I can use gridDestroy to kill everything when I switch between small arms data and chemical weapon data.  What I am trying to do is use a conditional statement that will drive when to use either one.  But I am stuck.  Does jqGrid set a variable (no matter where the grid gets built) that I can test for??? That way I can cut down on processing time to rebuild the grid only when absolutely necessary.

Tony