Any Idea why this is not working? Uses linked_messages

If anyone has some idea as to why this code does not work I would love to hear it. What this code does not show is the linked prims message they send. but it is a fairly simple message and the debug text shows the messages are getting transmitted just fine. So it is in this part of the script that the error is arising:

// Set global Variables
integer     Repeat;
vector      TargetPosition;
rotation    Level;
integer     Switch;

default
{
    state_entry()
    {
        llSay(DEBUG_CHANNEL, "Platform Ready.");
    }
    link_message(integer sender_num, integer Num, string Report, key ID)
    {
//Debug Info
        llSay(DEBUG_CHANNEL, "Message: " + Report +"\n PrimNum: " +(string) sender_num + "\n Switch: " +(string) Switch);

//Change the Switch

        if ( sender_num = 4)
        {
            Switch  = 1;
        }
        
        if (sender_num = 3)
        {
            Switch  = -1;
        }

// Move it

        llSetStatus(STATUS_PHYSICS, TRUE);
        for(Repeat= 0; Repeat<50; Repeat+=1)
        {        
             TargetPosition = llGetPos();
             TargetPosition.z = TargetPosition.z + (50 * Switch);
             llMoveToTarget(TargetPosition, 1);
             if (TargetPosition.z > 100)
             {
                 Repeat =500;
             }
        }

    }
}

Edit: What the debug message tells me is that the Switch Variable is Not changing. Why it isn't I have no clue.

These guys:

if ( sender_num = 4)
{
Switch = 1;
}

if (sender_num = 3)
{
Switch = -1;
}

Should likely be:

if ( sender_num == 4)
{
Switch = 1;
}

if (sender_num == 3)
{
Switch = -1;
}

I figured it was a foolish little oversight and it sure enough was.

Thanks for pointing that out =^_^=

No telling how many years it would have taken me to notice >.>

a little cleanup, if your just checking a value, like you are, don't use if... if... instead use if.. else if... this will save the code from executing every time that it goes though. Basically if the first statement is true, it won't bother to check the second statement if you use if else if.

if ( sender_num == 4)
{
     Switch = 1;
}

else if (sender_num == 3)
{
     Switch = -1;
}

so if sender_num is 4, the code won't even bother to make a check after it has finished the true statement of the block in the if (sender_num == 4), it will skip past the
else if (sender_num == 3) block.

Just a helpful little hint when you have a whole bunch of if statements and your only checking one thing. It will speed up the execution time a little.

/me nods.. = is for when you want to assign a value to a variable, == is for when you want to test the value of a variable.

This is while some people would have written it like "if (3 == sender_num)" instead. That will generate a compile-time error if you use = by mistake.