Age Validation in JavaScipt

//age handling
var dob = $(“#date_of_birth”).val();
var arr = dob.split(‘-‘);

var day = arr[0];
var month = arr[1];
var year = arr[2];
var age = 18; //allowed age
var mydate = new Date();
mydate.setFullYear(year, month-1, day);
var currdate = new Date();
currdate.setFullYear(currdate.getFullYear() – age);

if ((currdate – mydate) < 0){
alert(“Your age should be greater than 18 years for registration “);
is_error = true;
return false;
}
//age handling