I want to do year validation whre it should be only numeric and Its should be 4 digit long and between 1920 to current year for that I have create Javascript function as follows:

function yearValidation(year) {

    var text = /^[0-9]+$/;

    if (year != 0) {

        if ((year != ) && (!text.test(year))) {



            alert(Please Enter Numeric Values Only);

            return false;

        }



        if (year.length != 4) {

            alert(Year is not proper. Please check);

            return false;

        }

        var current_year=new Date().getFullYear();

        if((year < 1920) || (year > current_year))

            {

            alert(Year should be in range 1920 to current year);

            return false;

            }

        return true;

    }

and called it on onkeypress=return yearValidation(this.value)

But when I enter 1 it gives me alert:

Year should be in range 1920 to current year