mvc angularjs settimeout taking moretime to execute

I have popup when i click the OK button then it has to hide and execute the following function.

function timer1()
{
var animation =3000;
if(!$scope.isvalid)
{
$("#info").addclass('info');
setTimeout(function (){
$("#info").removeclass('info');},20);
});
}
}

it works fine for me. when i click OK button css will fire and display error message for 30 seconds. But the problem is when i click OK button from popup it's not hiding immediately taking more time to hide. please post the answer if any body knows. why it's taking more time to hide.