Bizare behavior from simple script

I can't for the life of me figure out why this script dosent work like it shoud.
whisper results:
on compile - initalizing counter
first touch - nothing
each susequent touche - closing, opening, opened
-door also moved in local +x direction each time

//**********************************************
//Title: Barn door left
//Author: Samantha Fuller 9/18/06
// Version 1
//**********************************************

string CLOSE;
string OPEN;
integer num_knocks;
integer shut = TRUE;
default
{
   state_entry()
    {
        num_knocks = 0; // initalize counter
        llWhisper(0, "initalizing counter");
    }
    
    touch_start(integer num_detected)
    {
        ++ num_knocks;
        if(num_knocks = 1)
        {
            //other door is the same except door movement direction
            llMessageLinked(LINK_SET, 0, "CLOSE", NULL_KEY);
            llWhisper(0, "Closeing");
        }

        if(num_knocks = 2)
        {
            llMessageLinked(LINK_SET, 0, "OPEN", NULL_KEY);
            llWhisper(0, "Opening");
        }
        
        if(num_knocks >=3 )
        {
            llWhisper(0, "reset to default");
            state reset_to_default;
        }
    }
    
    link_message(integer sender_num, integer num, string str, key id)
    {
        if(str == "CLOSE")
        {
            if(shut = FALSE)
            {
                //llSetRot(llGetLocalRot() + <1,0,0,0>);
                llSetPos(llGetLocalPos() + <2,0,0>);
                llWhisper(0, "Closed");
                //llMessageLinked(LINK_ALL_OTHERS, 0, "closed", NULL_KEY);
                shut = TRUE;
            }
        }
        if(str == "OPEN")
        {
            if(shut = TRUE)
            {
                //llSetRot(llGetLocalRot() + <1,0,0,0>);
                llSetPos(llGetLocalPos() + <-2,0,0>);
                llWhisper(0, "Opened");
                //llMessageLinked(LINK_ALL_OTHERS, 0, "open", NULL_KEY);
                shut = FALSE;
            }  //close verification toggel
        } //close str mesage                                           
    }  //close link_mesage
} //close defualt state

state reset_to_default
{
    state_entry()
    {
        //this state exist because default canot be called from itself
        llWhisper(0, "default");
        state default;
    }
} 

in your if statements you have = not ==, so your assigning that number to whatever it is, and that returns true, you want to change those ='s to ==.

//**********************************************
//Title: Barn door left
//Author: Samantha Fuller 9/18/06
// Version 1
//**********************************************

string CLOSE;
string OPEN;
integer num_knocks;
integer shut = TRUE;
default
{
   state_entry()
    {
        num_knocks = 0; // initalize counter
        llWhisper(0, "initalizing counter");
    }
    
    touch_start(integer num_detected)
    {
        ++ num_knocks;
        if(num_knocks == 1)
        {
            //other door is the same except door movement direction
            llMessageLinked(LINK_SET, 0, "CLOSE", NULL_KEY);
            llWhisper(0, "Closeing");
        }

        if(num_knocks == 2)
        {
            llMessageLinked(LINK_SET, 0, "OPEN", NULL_KEY);
            llWhisper(0, "Opening");
        }
        
        if(num_knocks >=3 )
        {
            llWhisper(0, "reset to default");
            state reset_to_default;
        }
    }
    
    link_message(integer sender_num, integer num, string str, key id)
    {
        if(str == "CLOSE")
        {
            if(shut == FALSE)
            {
                //llSetRot(llGetLocalRot() + <1,0,0,0>);
                llSetPos(llGetLocalPos() + <2,0,0>);
                llWhisper(0, "Closed");
                //llMessageLinked(LINK_ALL_OTHERS, 0, "closed", NULL_KEY);
                shut = TRUE;
            }
        }
        if(str == "OPEN")
        {
            if(shut == TRUE)
            {
                //llSetRot(llGetLocalRot() + <1,0,0,0>);
                llSetPos(llGetLocalPos() + <-2,0,0>);
                llWhisper(0, "Opened");
                //llMessageLinked(LINK_ALL_OTHERS, 0, "open", NULL_KEY);
                shut = FALSE;
            }  //close verification toggel
        } //close str mesage                                           
    }  //close link_mesage
} //close defualt state

state reset_to_default
{
    state_entry()
    {
        //this state exist because default canot be called from itself
        llWhisper(0, "default");
        state default;
    }
} 

Thank you very much.

Though i had to also add a line to the second if conditional, reseting the counter to get the script to behave like i wanted.

It is hard for pepole new to programing to think like a computer.

Not as hard as it is for a computer to think like a human.

Mixing up the equality operator (==) and assignment operator (=) is probably the most common bug. A way to help protect against this is to always put the constant on the LHS, i.e.

instead of

if(value == 2){ dosomething; }

use

if(2 == value)){ dosomething; }

That way if you do get it wrong the compiler will tell you. of course if your checking 2 variables for equality you're on your own again!