how to give alert of yes and No in js? code example

Example 1: javascript confirm yes no

var proceed = confirm("Are you sure you want to proceed?");
if (proceed) {
  //proceed
} else {
  //don't proceed
}

Example 2: how to take yes or no in js

ans = confirm('continue ?');
//returns a boolean response
if (ans){
	//condition returns true...
}
else(){
	//condition returns false...
}