I have 2 buttons and 2 voids (blink_slow) (blink_fast). i need to be able to press button 1 and blink-slow void will run, then press button 2 and blink fast will run. none of my code works, any idea how i can do this?

const int btn1 1;
const int btn2 2;
const int led  13;

void setup(){
pinMode(btn1,INPUT_PULLUP);
pinMode(btn2,INPUT_PULLUP);
pinMode(led,OUTPUT);
digitalWrite(led,HIGH);
}
void loop(){
if(digitalRead(btn2 =LOW)){
blink_slow();
}
if(digitalRead(btn3 =LOW)){
blink_fast();
}

void blink_slow(){
digitalWrite(led,LOW);
delay(1000)
digitalWrite(led,HIGH);
delay(1000)
}

void blink_fast(){
digitalWrite(led,LOW);
delay(500)
digitalWrite(led,HIGH);
delay(500)
}