Hi everyone ! 
i have created a simple program to change the state of an LED using a switch. it worked but not at all.
I just want to know why not working properly? Thanks !
int sw=4;
int led=5;
int st=0;
void setup(){
pinMode(sw,INPUT);
pinMode(led,OUTPUT);
}
void loop(){
if(digitalRead(sw)==HIGH){
st=~st;
}
while(digitalRead(sw)==HIGH){}
digitalWrite(led,st);
}