Led Burning with Button (On Off)

1int ledState = 0;
2
3void setup() {
4  pinMode(13, INPUT);
5  pinMode(7, OUTPUT);
6}
7
8void loop() {  
9  if (digitalRead(13) == 1) {
10    ledState = !ledState;
11    digitalWrite(7, ledState);
12    delay(300);
13  }   
14}