having trouble loading sketch

having trouble loading sketch i keep getting this

avrdude: stk500v2_disable(); failed to leave programing mode

following projects out of the book getting started with arduino
first one i did loaded but now i am not sure if it loading them at all hears the one i am doing right now.

i am also wondering i want to mount my board but i do not know how i should mount it to or how to space it and what to space it with.

ps. any help and or suggestion will be helpful. and think u in advance for your help.

// turn on led when the button is pressed
// and keep it on after it is released
// now with a new and improved formula!

const int LED = 13; // the pin for the LED
const int BUTTON = 7; // the input pin were the
// pushbutton is connected
int val = 0; // val will be used to store the state
// of the input pin
int old_val = 0; // this variable stores the previous
// value of "val"
int state = 0; // LED off and 1 = LED on

void setup(){
pinMode(LED, OUTPUT); // tell arduino LED is an input
pinMode(BUTTON, INPUT); // and BUTTON is an input
}
void loop(){
val = digitalRead(BUTTON); // read input value and store it

// check if there was a transition
if ((val == HIGH) && (old_val == LOW)){
state = 1 - state;
delay(10);
}

old_val = val; // val is now old, let's store it

if (state ==1) {
digitalWrite(LED, HIGH); // turn led on
}
else{
digitalWrite(LED, LOW);
}
}