help with else if in a timer event

I made an airmattress that I'm trying to move back and forth between to positions using a timer event and changing the vector offset in llMoveToTarget. I added a few llSay for debuging. The script complies ok and when started the airmattress makes a few initial movements than holds at one positon. In chat I'll see "bottom" "first stop" repeated without ever seeing "second stop". Can someone tell what I have messed up and why the "else if" part of the timer event doesn't seem to be executing? Please bare in mind that I'm real new to scripting and any help if greatly appreicated.

vector offsetA =<-3,0,0>;
vector offsetB =<-7,0,0>;
string test = "";


default
{
    state_entry()
    {
        test="top";
        vector pos = llGetPos();
        llSetStatus(STATUS_PHYSICS, TRUE);
        llSetBuoyancy(1.0);
        llSleep(0.1);
        llSetTimerEvent(10.0);
    }
    timer()
    {
        llSay(0,test);  //added for debug
        if (test = "top")
          {
           test = "bottom";  
           llSay(0,"first stop");  //added for debug   
           vector pos = llDetectedPos(0);
          (pos+= offsetB);
          llMoveToTarget(pos,2.4);
        }
    
        else if (test = "bottom")  
           {
            test = "top";
            llSay(0,"second stop");  //added for debug  
            vector pos = llDetectedPos(0);
           (pos+= offsetA);
           llMoveToTarget(pos,2.4);
                  
    }
}   

}

that's because in the if test you are declaring test to "top" again

if(test = "top" should be
if(test == "top"

likewise with the bottom test

You are using the assignment "=" in the if tests: you should be using the comparator "==". Also, you should be using llGetPos () to determine the object's current position and not llDetectedPos (0), which only works with some events, and timer is not one of them.

Thanks very much for the quick replies. I know it was prob something fairly basic